AzTrials
AzTrials

COVID-19Phase 2/3AZD2816NCT04973449

Phase II/III Study of AZD2816, for the Prevention of COVID-19 in Adults

A Phase 2/3 study testing AZD1222 and AZD2816 in people with COVID-19 and SARS-CoV-2, run by AstraZeneca at 35 sites in 4 countries.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
Search all trials

Trial summary

The aim of the study is to assess the safety, and immunogenicity of AZD2816 for the prevention of coronavirus disease 2019 (COVID-19). Read more about this study

Who is it for?
Ages 18 to 115 yearsHealthy volunteers can take part
Conditions the study is for
COVID-19, SARS-CoV-2
What is being tested?
AZD1222 and AZD2816
Could I receive a placebo?
No, everyone receives an active treatment
How many people
2,843 participants
Where
35 sitesin 4 countries
Study dates
27 Jun 2021to 2 Aug 2022
Phase
Phase 2/3
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 115 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Adult, ≥ 18 years of age at the time of consent.
  • For inclusion in the SARS-CoV-2 seronegative population:
  • No history of laboratory-confirmed SARS-CoV-2 infection (ie, no positive nucleic acid amplification test and no positive antibody test).
  • Seronegative for SARS-CoV-2 at screening (lateral flow test to detect reactivity to the nucleoprotein).
  • Medically stable such that, according to the judgment of the investigator, hospitalization within the study period is not anticipated and the participant appears likely to be able to remain on study through the end of protocol-specified follow-up.
  • Able to understand and comply with study requirements/procedures (if applicable, with assistance by caregiver, surrogate, or legally authorized representative) based on the assessment of the investigator.
Show all 10Show fewer
  • Signed informed consent obtained before conducting any study-related procedures.
  • Contraceptive use by women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies.
  • Previously COVID-19 Vaccinated Participants:
  • Prior completion of a 2-dose primary homologous vaccination regimen against SARSCoV-2 with either AZD1222 (2 standard doses as authorized vaccine or as investigational product in a clinical trial with a 4 to 12-week dosing interval) or with an mRNA vaccine approved for emergency or conditional use. The second dose in all cases should have been administered at least 3 months prior to first administration of study intervention.

Who cannot join

  • History of allergy to any component of AZD1222/AZD2816.
  • History of Guillain-Barré syndrome, any demyelinating disease, or any other neuroimmunologic condition.
  • Significant infection or other acute illness, including fever > 100 °F (> 37.8 °C) on the day prior to or day of randomization.
  • Any confirmed or suspected immunosuppressive or immunodeficient state, including asplenia or human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS).
  • Recurrent severe infections and use of immunosuppressant medication within the past 6 months (≥ 20 mg per day of prednisone or its equivalent, given daily or on alternate days for ≥ 15 days within 30 days prior to administration of study intervention). The following exceptions are permitted: Topical/inhaled steroids or short-term oral steroids (course lasting ≤ 14 days).
  • History of primary malignancy (see protocol).
Show all 12Show fewer
  • History of thrombocytopenia and/or thrombosis, including participants who have experienced major venous and/or arterial thrombosis in combination with thrombocytopenia following vaccination with any COVID-19 vaccine.
  • History of heparin-induced thrombocytopenia, congenital thrombophilia (ie, factor V Leiden, prothrombin G20210A, antithrombin III deficiency, protein C deficiency and protein S deficiency, factor XIII mutation, familial dysfibrinogenemia), auto-immune thrombophilia (antiphospholipid syndrome, anti-cardiolipin antibodies, anti-β2- glycoprotein 1 antibodies), or paroxysmal nocturnal haemoglobinuria.
  • Clinically significant bleeding (eg, factor deficiency, coagulopathy, or platelet disorder), or prior history of significant bleeding or bruising following intramuscular injections or venepuncture.
  • Severe and/or uncontrolled cardiovascular disease, respiratory disease, gastrointestinal disease, liver disease, renal disease, endocrine disorder, or neurological illness, as judged by the Investigator.
  • Any other significant disease, disorder, or finding that may significantly increase the risk to the participant because of participation in the study, affect the ability of the participant to participate in the study, or impair interpretation of the study data.
  • Any autoimmune conditions, except mild psoriasis and vitiligo.

Trial locations and contacts

35 sites in 4 countries.

35 sites in 4 countries

United Kingdom19 sites

  • Research Site

    Birmingham, B15 2TH

  • Research Site

    Bournemouth, BH7 7DW

  • Research Site

    Bristol, BS105NB

  • Research Site

    Bristol, BS2 8BJ

  • Research Site

    Edinburgh, EH16 4SA

  • Research Site

    Harrow, HA1 3UJ

  • Research Site

    Hull, HU3 2KZ

  • Research Site

    London, E2 0HL

  • Research Site

    London, NW1 2BH

  • Research Site

    London, SE1 9RT

  • Research Site

    London, SE5 9NU

  • Research Site

    Manchester, M8 5RB

  • Research Site

    Newcastle upon Tyne, NE1 4LP

  • Research Site

    Nottingham, NG7 2QW

  • Research Site

    Oxford, OX3 7EJ

  • Research Site

    Plymouth, PL6 8DH

  • Research Site

    Portsmouth, PO1 3HN

  • Research Site

    Sheffield, S5 7AU

  • Research Site

    Truro, TR1 3LJ

Other trials in United Kingdom

Brazil6 sites

  • Research Site

    Brasília, 70200-730

  • Research Site

    Curitiba, 80810-050

  • Research Site

    Natal, 59020-035

  • Research Site

    Natal, 59025-050

  • Research Site

    Porto Alegre, 90035-903

  • Research Site

    Salvador, 40110-060

Other trials in Brazil

South Africa6 sites

  • Research Site

    Bloemfontein, 9301

  • Research Site

    Cape Town, 7500

  • Research Site

    Johannesburg, 1818

  • Research Site

    Johannesburg, 2013

  • Research Site

    Johannesburg, 2092

  • Research Site

    Somerset West, 7130

Other trials in South Africa

Poland4 sites

  • Research Site

    Lublin, 20-362

  • Research Site

    Oświęcim, 32-600

  • Research Site

    Puławy, 24-100

  • Research Site

    Zamość, 22-400

Other trials in Poland

About this study

Official title: A Phase II/III Partially Double-Blinded, Randomised, Multinational, Active-Controlled Study in Both Previously Vaccinated and Unvaccinated Adults to Determine the Safety and Immunogenicity of AZD2816, a Vaccine for the Prevention of COVID-19 Caused by Variant Strains of SARS-CoV-2

The aim of the study is to assess the safety, and immunogenicity of AZD2816 for the prevention of coronavirus disease 2019 (COVID-19).

Read the detailed description

The purpose of this study is to demonstrate the safety and characterize the immunogenicity of AZD2816; AstraZeneca's candidate chimpanzee adenovirus Ox1 (ChAdOx1) vector vaccine against severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) variant strain B.1.351.

Conditions
COVID-19, SARS-CoV-2
Being tested
AZD1222, AZD2816
Keywords
COVID-19 Vaccine
Medical subject headings
COVID-19

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • AZD1222Biological

    10 mM histidine/histidine hydrochloride, 7.5% (w/v) sucrose, 35 mM sodium chloride, 1 mM magnesium chloride, 0.1% (w/v) polysorbate 80, 0.1 mM edetate disodium, 0.5% (w/v) ethanol, at pH 6.6.

  • AZD2816Biological

    10 mM histidine/histidine hydrochloride, 7.5% (w/v) sucrose, 35 mM sodium chloride, 1 mM magnesium chloride, 0.1% (w/v) polysorbate 80, 0.1 mM edetate disodium, 0.5% (w/v) ethanol, at pH 6.6.

Study groups in NCT04973449
Study groupRoleWhat they receive
Primary Vaccination Cohort:- AZD1222 (4)ExperimentalPreviously unvaccinated participants received intramuscular (IM) AZD1222 5*10^10 viral particles (vp) on Days 1 and 29 (4-week dosing interval).
Receives: Biological: AZD1222
Primary Vaccination Cohort:- AZD2816 (4)ExperimentalPreviously unvaccinated participants received IM AZD2816 5*10^10 vp on Days 1 and 29 (4-week dosing interval).
Receives: Biological: AZD2816
Primary Vaccination Cohort:- AZD1222 + AZD2816 (4)ExperimentalPreviously unvaccinated participants received IM AZD1222 5*10^10 vp on Day 1 and IM AZD2816 5*10^10 vp on Day 29 (4-week dosing interval).
Receives: Biological: AZD1222; Biological: AZD2816
Primary Vaccination Cohort:- AZD2816 (12)ExperimentalPreviously unvaccinated participants received IM AZD2816 5*10^10 vp on Days 1 and 85 (12-week dosing interval).
Receives: Biological: AZD2816
Booster Cohort:- AZD1222:AZD1222ExperimentalParticipants, who previously received 2 doses of AZD1222 vaccine according to the authorized dose and dosing regimen, with second dose administered at least 90 days prior to study treatment, received booster dose of IM AZD1222 5*10^10 vp on Day 1.
Receives: Biological: AZD1222
Booster Cohort:- AZD1222:AZD2816ExperimentalParticipants, who previously received 2 doses of AZD1222 vaccine according to the authorized dose and dosing regimen, with second dose administered at least 90 days prior to study treatment, received booster dose of IM AZD2816 5*10^10 vp on Day 1.
Receives: Biological: AZD2816
Booster Cohort:- mRNA:AZD1222ExperimentalParticipants, who previously received 2 doses of approved mRNA based vaccine according to the authorized dose and dosing regimen, with second dose administered at least 90 days prior to study treatment, received booster dose of IM AZD1222 5*10^10 vp on Day 1.
Receives: Biological: AZD1222
Booster Cohort:- mRNA:AZD2816ExperimentalParticipants, who previously received 2 doses of approved mRNA based vaccine according to the authorized dose and dosing regimen, with second dose administered at least 90 days prior to study treatment, received booster dose of IM AZD2816 5*10^10 vp on Day 1.
Receives: Biological: AZD2816

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Number of Participants With Local and Systemic Solicited Treatment Emergent Adverse Events (TEAEs) in Primary Vaccination Cohort (PVC):- AZD2816 (4), Booster Cohorts:-AZD1222:AZD2816, and mRNA:AZD2816

    An adverse event (AE) is any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. The TEAEs are defined as events present at baseline that worsened in intensity after administration of study drug or events absent at baseline that emerged after administration of study drug. Solicited AEs are local or systemic predefined events for assessment of reactogenicity. An e-diary was used to collect information on the timing and severity of the solicited AEs. Local AEs included pain, redness/erythema, tenderness, induration/swelling at the site of the injection. Systemic AEs included fever (> 100 °F/37.8 °C), chills, muscle pains, fatigue, headache, malaise, nausea, and vomiting.

    Measured: During the 7-day follow-up period after vaccination (vaccines administered on Days 1 and 29 [only for primary vaccination cohort])

  2. Number of Participants With Unsolicited TEAEs, Treatment-emergent Serious AEs (TESAEs), Medically Attended AEs (MAAEs), and Adverse Events of Special Interest (AESIs) in PVC:- AZD2816 (4), Booster Cohorts:- AZD1222:AZD2816, and mRNA:AZD2816

    The AEs other than solicited AEs are reported as unsolicited AEs and were collected by "open question" at study visits. AE: any untoward medical occurrence in participant who received study drug without regard to possibility of causal relationship. TEAEs: events present at baseline that worsened in intensity after administration of study drug or events absent at baseline that emerged after administration of study drug. SAE: an AE resulting in any of following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life threatening experience; persistent or significant disability/incapacity; congenital anomaly. MAAE: an AE leading to a non-routine/unscheduled medically-attended visit, to or from medical doctor for any reason. AESI: an event of scientific and medical interest specific to further understanding of study drug safety profile and require close monitoring and rapid communication by investigators to Sponsor.

    Measured: During the 28-day follow-up period after vaccination (vaccines administered on Days 1 and 29 [only for primary vaccination cohort])

  3. Number of Participants With Abnormal Laboratory Parameters Reported as TEAEs in Primary Vaccination Cohort:- AZD2816 (4), Booster Cohorts:-AZD1222:AZD2816 and mRNA:AZD2816

    Number of participants with abnormal laboratory parameters reported as TEAEs are reported. Laboratory tests included haematology and clinical chemistry.

    Measured: During the 28-day follow-up period after vaccination (vaccines administered on Days 1 and 29 [only for primary vaccination cohort])

  4. Geometric Mean Titre (GMT) of SARS-CoV-2 Neutralizing Antibodies (nAb) Against B.1.351 Variant Elicited by Primary Vaccination Cohort:- AZD2816 (4) and the Original Wuhan-Hu-1 Strain Elicited by Primary Vaccination Cohort:- AZD1222 (4)

    Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Primary Vaccination Cohort:- AZD2816 (4) with response against B.1.351 variant is the comparator group and Primary Vaccination Cohort:- AZD1222 (4) with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: 28 days after second dose (Day 57)

  5. GMT of SARS-CoV-2 nAb Against the Original Wuhan-Hu-1 Strain Elicited by Booster Cohort:- AZD1222:AZD1222 and AZD1222 in Historical Control

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Booster Cohort:- AZD1222:AZD1222 is the comparator group and AZD1222 in Historical Control is the reference group, both compared for response against the original Wuhan-Hu-1 strain.

    Measured: Booster Cohort: 28 days after booster dose (Day 29) and Historical Control: 28 days after the second dose (Day 57)

  6. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against the B.1.351 Variant Elicited by Primary Vaccination Cohort:- AZD2816 (4) and the Original Wuhan-Hu-1 Strain Elicited by Primary Vaccination Cohort:- AZD1222 (4)

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Primary Vaccination Cohort:- AZD2816 (4) with response against B.1.351 variant is the comparator group and Primary Vaccination Cohort:- AZD1222 (4) with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: 28 days after second dose (Day 57)

  7. GMT of SARS-CoV-2 nAb Against the Original Wuhan-Hu-1 Strain Elicited by Booster Cohort:- mRNA:AZD1222 and AZD1222 in Historical Control

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Booster Cohort:- mRNA:AZD1222 is the comparator group and AZD1222 in Historical Control is the reference group, both compared for response against the original Wuhan-Hu-1 strain.

    Measured: Booster Cohort: 28 days after booster dose (Day 29) and Historical Control: 28 days after the second dose (Day 57)

Secondary outcomes (64)

  1. Number of Participants With Local and Systemic Solicited TEAEs

    An AE is any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. The TEAEs are defined as events present at baseline that worsened in intensity after administration of study drug or events absent at baseline that emerged after administration of study drug. Solicited AEs are local or systemic predefined events for assessment of reactogenicity. An e-diary was used to collect information on the timing and severity of the solicited AEs. Local AEs included pain, redness/erythema, tenderness, induration/swelling at the site of the injection. Systemic AEs included fever (> 100 °F/37.8 °C), chills, muscle pains, fatigue, headache, malaise, nausea, and vomiting.

    Measured: During the 7-day follow-up period after vaccination (vaccines administered on Days 1 and 29 or Day 85 [only for primary vaccination cohorts])

  2. Number of Participants With Unsolicited TEAEs, TESAEs, MAAEs, and AESIs

    The AEs other than solicited AEs are reported as unsolicited AEs and were collected by "open question" at study visits. AE: any untoward medical occurrence in participant who received study drug without regard to possibility of causal relationship. TEAEs: events present at baseline that worsened in intensity after administration of study drug or events absent at baseline that emerged after administration of study drug. SAE: an AE resulting in any of following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life threatening experience; persistent or significant disability/incapacity; congenital anomaly. MAAE: an AE leading to a non-routine/unscheduled medically-attended visit, to or from medical doctor for any reason. AESI: an event of scientific and medical interest specific to further understanding of study drug safety profile and require close monitoring and rapid communication by investigators to Sponsor.

    Measured: During the 28-day follow-up period after vaccination (vaccines administered on Days 1 and 29 or Day 85 [only for primary vaccination cohorts])

  3. GMT of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Primary Vaccination Cohort:- AZD2816 (4) and Primary Vaccination Cohort:- AZD1222 (4)

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Primary Vaccination Cohort:- AZD2816 (4) is the comparator group and Primary Vaccination Cohort:- AZD1222 (4) is the reference group, both compared for response against B.1.351 variant.

    Measured: 28 days after second dose (Day 57)

  4. GMT of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Primary Vaccination Cohort:- AZD1222 + AZD2816 (4) and the Original Wuhan-Hu-1 Strain Elicited by Primary Vaccination Cohort:- AZD1222 (4)

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Primary Vaccination Cohort:- AZD1222 + AZD2816 (4) with response against B.1.351 variant is the comparator group and Primary Vaccination Cohort:- AZD1222 (4) with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: 28 days after second dose (Day 57)

  5. GMT of SARS-CoV-2 nAb Against the Original Wuhan-Hu-1 Strain Elicited by Primary Vaccination Cohort:- AZD2816 (4) and Primary Vaccination Cohort:- AZD1222 (4)

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Primary Vaccination Cohort:- AZD2816 (4) is the comparator group and Primary Vaccination Cohort:- AZD1222 (4) is the reference group, both compared for response against the original Wuhan-Hu-1 strain.

    Measured: 28 days after second dose (Day 57)

  6. GMT of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Booster Cohort:- AZD1222:AZD2816 and the Original Wuhan-Hu-1 Strain Elicited by AZD1222 in Historical Control

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Booster Cohort:- AZD1222:AZD2816 with response against B.1.351 variant is the comparator group and AZD1222 in Historical Control with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: Booster Cohort: 28 days after booster dose (Day 29) and Historical Control: 28 days after the second dose (Day 57)

  7. GMT of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Booster Cohort:- AZD1222:AZD2816 and Booster Cohort:- AZD1222:AZD1222

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Booster Cohort:- AZD1222:AZD2816 is the comparator group and Booster Cohort:- AZD1222:AZD1222 is the reference group, both compared for response against B.1.351 variant.

    Measured: 28 days after booster dose (Day 29)

  8. GMT of SARS-CoV-2 nAb Against the Original Wuhan-Hu-1 Strain Elicited by Booster Cohort:- AZD1222:AZD2816 and AZD1222 in Historical Control

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Booster Cohort:- AZD1222:AZD2816 is the comparator group and AZD1222 in Historical Control is the reference group, both compared for response against the original Wuhan-Hu-1 strain.

    Measured: Booster Cohort: 28 days after booster dose (Day 29) and Historical Control: 28 days after the second dose (Day 57)

  9. GMT of SARS-CoV-2 nAb Against the Original Wuhan-Hu-1 Strain Elicited by Booster Cohort:- AZD1222:AZD2816 and Booster Cohort:- AZD1222:AZD1222

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Booster Cohort:- AZD1222:AZD2816 is the comparator group and Booster Cohort:- AZD1222:AZD1222 is the reference group, both compared for response against the original Wuhan-Hu-1 strain.

    Measured: 28 days after booster dose (Day 29)

  10. GMT of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Booster Cohort:- AZD1222:AZD2816 and Primary Vaccination Cohort:- AZD1222 (4)

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Booster Cohort:- AZD1222:AZD2816 is the comparator group and Primary Vaccination Cohort:- AZD1222 (4) is the reference group, both compared for response against B.1.351 variant.

    Measured: Booster Cohort: 28 days after booster dose (Day 29) and Primary Vaccination Cohort: 28 days after the second dose (Day 57)

  11. GMT of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Booster Cohort:- mRNA:AZD2816 and the Original Wuhan-Hu-1 Strain Elicited by AZD1222 in Historical Control

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Booster Cohort:- mRNA:AZD2816 with response against B.1.351 variant is the comparator group and AZD1222 in Historical Control with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: Booster Cohort: 28 days after booster dose (Day 29) and Historical Control: 28 days after the second dose (Day 57)

  12. GMT of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Booster Cohort:- mRNA:AZD2816 and Booster Cohort:- mRNA:AZD1222

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Booster Cohort:- mRNA:AZD2816 is the comparator group and Booster Cohort:- mRNA:AZD1222 is the reference group, both compared for response against B.1.351 variant.

    Measured: 28 days after booster dose (Day 29)

  13. GMT of SARS-CoV-2 nAb Against the Original Wuhan-Hu-1 Strain Elicited by Booster Cohort:- mRNA:AZD2816 and AZD1222 in Historical Control

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Booster Cohort:- mRNA:AZD2816 is the comparator group and AZD1222 in Historical Control is the reference group, both compared for response against the original Wuhan-Hu-1 strain.

    Measured: Booster Cohort: 28 days after booster dose (Day 29) and Historical Control: 28 days after the second dose (Day 57)

  14. GMT of SARS-CoV-2 nAb Against the Original Wuhan-Hu-1 Strain Elicited by Booster Cohort:- mRNA:AZD2816 and Booster Cohort:- mRNA:AZD1222

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Booster Cohort:- mRNA:AZD2816 is the comparator group and Booster Cohort:- mRNA:AZD1222 is the reference group, both compared for response against the original Wuhan-Hu-1 strain.

    Measured: 28 days after booster dose (Day 29)

  15. GMT of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Booster Cohort:- mRNA:AZD2816 and Primary Vaccination Cohort:- AZD1222 (4)

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Booster Cohort:- mRNA:AZD2816 is the comparator group and Primary Vaccination Cohort:- AZD1222 (4) is the reference group, both compared for response against B.1.351 variant.

    Measured: Booster Cohort: 28 days after booster dose (Day 29) and Primary Vaccination Cohort: 28 days after the second dose (Day 57)

  16. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Booster Cohort:- AZD1222:AZD2816 and the Original Wuhan-Hu-1 Strain Elicited by AZD1222 in Historical Control

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Booster Cohort:- AZD1222:AZD2816 with response against B.1.351 variant is the comparator group and AZD1222 in Historical Control with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: Booster Cohort: 28 days after booster dose (Day 29) and Historical Control: 28 days after the second dose (Day 57)

  17. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Booster Cohort:- AZD1222:AZD2816 and Booster Cohort:- AZD1222:AZD1222

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Booster Cohort:- AZD1222:AZD2816 is the comparator group and Booster Cohort:- AZD1222:AZD1222 is the reference group, both compared for response against B.1.351 variant.

    Measured: 28 days after booster dose (Day 29)

  18. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against the Original Wuhan-Hu-1 Strain Elicited by Booster Cohort:- AZD1222:AZD2816 and AZD1222 in Historical Control

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Booster Cohort:- AZD1222:AZD2816 is the comparator group and AZD1222 in Historical Control is the reference group, both compared for response against the original Wuhan-Hu-1 strain.

    Measured: Booster Cohort: 28 days after booster dose (Day 29) and Historical Control: 28 days after the second dose (Day 57)

  19. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against the Original Wuhan-Hu-1 Strain Elicited by Booster Cohort:- AZD1222:AZD2816 and Booster Cohort:- AZD1222:AZD1222

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Booster Cohort:- AZD1222:AZD2816 is the comparator group and Booster Cohort:- AZD1222:AZD1222 is the reference group, both compared for response against the original Wuhan-Hu-1 strain.

    Measured: 28 days after booster dose (Day 29)

  20. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Booster Cohort:- AZD1222:AZD2816 and Primary Vaccination Cohort:- AZD1222 (4)

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Booster Cohort:- AZD1222:AZD2816 is the comparator group and Primary Vaccination Cohort:- AZD1222 (4) is the reference group, both compared for response against B.1.351 variant.

    Measured: Booster Cohort: 28 days after booster dose (Day 29) and Primary Vaccination Cohort: 28 days after the second dose (Day 57)

  21. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Booster Cohort:- mRNA:AZD2816 and the Original Wuhan-Hu-1 Strain Elicited by AZD1222 in Historical Control

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Booster Cohort:- mRNA:AZD2816 with response against B.1.351 variant is the comparator group and AZD1222 in Historical Control with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: Booster Cohort: 28 days after booster dose (Day 29) and Historical Control: 28 days after the second dose (Day 57)

  22. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Booster Cohort:- mRNA:AZD2816 and Booster Cohort:- mRNA:AZD1222

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Booster Cohort:- mRNA:AZD2816 is the comparator group and Booster Cohort:- mRNA:AZD1222 is the reference group, both compared for response against B.1.351 variant.

    Measured: 28 days after booster dose (Day 29)

  23. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against the Original Wuhan-Hu-1 Strain Elicited by Booster Cohort:- mRNA:AZD2816 and AZD1222 in Historical Control

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Booster Cohort:- mRNA:AZD2816 is the comparator group and AZD1222 in Historical Control is the reference group, both compared for response against the original Wuhan-Hu-1 strain.

    Measured: Booster Cohort: 28 days after booster dose (Day 29) and Historical Control: 28 days after the second dose (Day 57)

  24. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against the Original Wuhan-Hu-1 Strain Elicited by Booster Cohort:- mRNA:AZD2816 and Booster Cohort:- mRNA:AZD1222

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Booster Cohort:- mRNA:AZD2816 is the comparator group and Booster Cohort:- mRNA:AZD1222 is the reference group, both compared for response against the original Wuhan-Hu-1 strain.

    Measured: 28 days after booster dose (Day 29)

  25. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Booster Cohort:- mRNA:AZD2816 and Primary Vaccination Cohort:- AZD1222 (4)

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Booster Cohort:- mRNA:AZD2816 is the comparator group and Primary Vaccination Cohort:- AZD1222 (4) is the reference group, both compared for response against B.1.351 variant.

    Measured: Booster Cohort: 28 days after booster dose (Day 29) and Primary Vaccination Cohort: 28 days after the second dose (Day 57)

  26. Number of Participants With TESAEs, MAAEs, and AESIs From Day 1 Through 6 Months Post Last Dose

    An AE is any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. An SAE is an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. The TEAEs are defined as events present at baseline that worsened in intensity after administration of study drug or events absent at baseline that emerged after administration of study drug. The MAAEs are defined as AEs leading to medically-attended visits that were not routine visits, or an otherwise unscheduled visit to or from medical doctor for any reason. The AESIs are events of scientific and medical interest specific to the further understanding of study drug safety profile and require close monitoring and rapid communication by the investigators to the Sponsor.

    Measured: During the 6 months follow-up period after vaccination (vaccines administered on Days 1 and 29 or Day 85 [only for primary vaccination cohorts])

  27. GMT of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Primary Vaccination Cohort:- AZD1222 + AZD2816 (4) and Primary Vaccination Cohort:- AZD1222 (4)

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Primary Vaccination Cohort:- AZD1222 + AZD2816 (4) is the comparator group and Primary Vaccination Cohort:- AZD1222 (4) is the reference group, both compared for response against B.1.351 variant.

    Measured: 28 days after second dose (Day 57)

  28. GMT of SARS-CoV-2 nAb Against the Original Wuhan-Hu-1 Strain Elicited by Primary Vaccination Cohort:- AZD1222 + AZD2816 (4) and Primary Vaccination Cohort:- AZD1222 (4)

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Primary Vaccination Cohort:- AZD1222 + AZD2816 (4) is the comparator group and Primary Vaccination Cohort:- AZD1222 (4) is the reference group, both compared for response against the Original Wuhan-Hu-1 Strain.

    Measured: 28 days after second dose (Day 57)

  29. GMT of SARS-CoV-2 nAb Against B.1.351 Variant and the Original Wuhan-Hu-1 Strain Elicited by Primary Vaccination Cohort:- AZD2816 (4)

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Primary Vaccination Cohort:- AZD2816 (4) with response against B.1.351 variant is the comparator group and Primary Vaccination Cohort:- AZD2816 (4) with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: 28 days after second dose (Day 57)

  30. GMT of SARS-CoV-2 nAb Against the B.1.351 Variant and the Original Wuhan-Hu-1 Strain by Primary Vaccination Cohort:- AZD1222 + AZD2816 (4)

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Primary Vaccination Cohort:- AZD1222 + AZD2816 (4) with response against B.1.351 variant is the comparator group and Primary Vaccination Cohort:- AZD1222 + AZD2816 (4) with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: 28 days after second dose (Day 57)

  31. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Primary Vaccination Cohort:- AZD2816 (4) and Primary Vaccination Cohort:- AZD1222 (4)

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Primary Vaccination Cohort:- AZD2816 (4) is the comparator group and Primary Vaccination Cohort:- AZD1222 (4) is the reference group, both compared for response against B.1.351 variant.

    Measured: 28 days after second dose (Day 57)

  32. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against the Original Wuhan-Hu-1 Strain Elicited by Primary Vaccination Cohort:- AZD2816 (4) and Primary Vaccination Cohort:- AZD1222 (4)

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Primary Vaccination Cohort:- AZD2816 (4) is the comparator group and Primary Vaccination Cohort:- AZD1222 (4) is the reference group, both compared for response against the original Wuhan-Hu-1 strain.

    Measured: 28 days after second dose (Day 57)

  33. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Primary Vaccination Cohort:- AZD1222 + AZD2816 (4) and the Original Wuhan Hu-1 Strain Elicited by Primary Vaccination Cohort:- AZD1222 (4)

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Primary Vaccination Cohort:- AZD1222 + AZD2816 (4) with response against B.1.351 variant is the comparator group and Primary Vaccination Cohort:- AZD1222 (4) with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: 28 days after second dose (Day 57)

  34. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Primary Vaccination Cohort:- AZD1222 + AZD2816 (4) and Primary Vaccination Cohort:- AZD1222 (4)

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Primary Vaccination Cohort:- AZD1222 + AZD2816 (4) is the comparator group and Primary Vaccination Cohort:- AZD1222 (4) is the reference group, both compared for response against B.1.351 variant.

    Measured: 28 days after second dose (Day 57)

  35. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against the Original Wuhan-Hu-1 Strain Elicited by Primary Vaccination Cohort:- AZD1222 + AZD2816 (4) and Primary Vaccination Cohort:- AZD1222 (4)

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Primary Vaccination Cohort:- AZD1222 + AZD2816 (4) is the comparator group and Primary Vaccination Cohort:- AZD1222 (4) is the reference group, both compared for response against the original Wuhan-Hu-1 strain.

    Measured: 28 days after second dose (Day 57)

  36. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against B.1.351 Variant and the Original Wuhan-Hu-1 Strain Elicited by Primary Vaccination Cohort:- AZD2816 (4)

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Primary Vaccination Cohort:- AZD2816 (4) with response against B.1.351 variant is the comparator group and Primary Vaccination Cohort:- AZD2816 (4) with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: 28 days after second dose (Day 57)

  37. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against B.1.351 Variant and the Original Wuhan-Hu-1 Strain Elicited by Primary Vaccination Cohort:- AZD1222 + AZD2816 (4)

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Primary Vaccination Cohort:- AZD1222 + AZD2816 (4) with response against B.1.351 variant is the comparator group and Primary Vaccination Cohort:- AZD1222 + AZD2816 (4) with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: 28 days after second dose (Day 57)

  38. GMT of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Booster Cohort:- AZD1222:AZD1222 and Primary Vaccination Cohort:- AZD1222 (4)

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Booster Cohort:- AZD1222:AZD1222 is the comparator group and Primary Vaccination Cohort:- AZD1222 (4) is the reference group, both compared for response against B.1.351 variant.

    Measured: Booster Cohort: 28 days after booster dose (Day 29) and Primary Vaccination Cohort: 28 days after the second dose (Day 57)

  39. GMT of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Booster Cohort:- AZD1222:AZD1222 and the Original Wuhan-Hu-1 Strain Elicited by AZD1222 in Historical Control

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Booster Cohort:- AZD1222:AZD1222 with response against B.1.351 variant is the comparator group and AZD1222 in Historical Control with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: Booster Cohort: 28 days after booster dose (Day 29) and Historical Control: 28 days after the second dose (Day 57)

  40. GMT of SARS-CoV-2 nAb Against the B.1.351 Variant and the Original Wuhan-Hu-1 Strain by Booster Cohort:- AZD1222:AZD2816

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Booster Cohort:- AZD1222:AZD2816 with response against B.1.351 variant is the comparator group and Booster Cohort:- AZD1222:AZD2816 with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: 28 days after second dose (Day 57)

  41. GMT of SARS-CoV-2 nAb Against the B.1.351 Variant and the Original Wuhan-Hu-1 Strain by Booster Cohort:- AZD1222:AZD1222

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information.Booster Cohort:- AZD1222:AZD1222 with response against B.1.351 variant is the comparator group and Booster Cohort:- AZD1222:AZD1222 with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: 28 days after second dose (Day 57)

  42. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against the Original Wuhan-Hu-1 Strain Elicited by Booster Cohort:- AZD1222:AZD1222 and AZD1222 in Historical Control

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Booster Cohort:- AZD1222:AZD1222 is the comparator group and AZD1222 in Historical Control is the reference group, both compared for response against the original Wuhan-Hu-1 strain.

    Measured: Booster Cohort: 28 days after booster dose (Day 29) and Historical Control: 28 days after the second dose (Day 57)

  43. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Booster Cohort:- AZD1222:AZD1222 and Primary Vaccination Cohort:- AZD1222 (4)

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Booster Cohort:- AZD1222:AZD1222 is the comparator group and Primary Vaccination Cohort:- AZD1222 (4) is the reference group, both compared for response against B.1.351 Variant.

    Measured: Booster Cohort: 28 days after booster dose (Day 29) and Primary Vaccination Cohort: 28 days after the second dose (Day 57)

  44. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Booster Cohort:- AZD1222:AZD1222 and the Original Wuhan-Hu-1 Strain Elicited by AZD1222 in Historical Control

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Booster Cohort:- AZD1222:AZD1222 with response against B.1.351 variant is the comparator group and AZD1222 in Historical Control with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: Booster Cohort: 28 days after booster dose (Day 29) and Historical Control: 28 days after the second dose (Day 57)

  45. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against B.1.351 Variant and the Original Wuhan-Hu-1 Strain Elicited by Booster Cohort:- AZD1222:AZD2816

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Booster Cohort:- AZD1222:AZD2816 with response against B.1.351 variant is the comparator group and Booster Cohort:- AZD1222:AZD2816 with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: 28 days after second dose (Day 57)

  46. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against B.1.351 Variant and the Original Wuhan-Hu-1 Strain Elicited by Booster Cohort:- AZD1222:AZD1222

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Booster Cohort:- AZD1222:AZD1222 with response against B.1.351 variant is the comparator group and Booster Cohort:- AZD1222:AZD1222 with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: 28 days after second dose (Day 57)

  47. GMT of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Booster Cohort:- mRNA:AZD1222 and Primary Vaccination Cohort:- AZD1222 (4)

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Booster Cohort:- mRNA:AZD1222 is the comparator group and Primary Vaccination Cohort:- AZD1222 (4) is the reference group, both compared for response against B.1.351 variant.

    Measured: Booster Cohort: 28 days after booster dose (Day 29) and Primary Vaccination Cohort: 28 days after the second dose (Day 57)

  48. GMT of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Booster Cohort:- mRNA:AZD1222 and the Original Wuhan-Hu-1 Strain Elicited by AZD1222 in Historical Control

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Booster Cohort:- mRNA:AZD1222 with response against B.1.351 variant is the comparator group and AZD1222 in Historical Control with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: Booster Cohort: 28 days after booster dose (Day 29) and Historical Control: 28 days after the second dose (Day 57)

  49. GMT of SARS-CoV-2 nAb Against the B.1.351 Variant and the Original Wuhan-Hu-1 Strain by Booster Cohort:- mRNA:AZD2816

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Booster Cohort:- mRNA:AZD2816 with response against B.1.351 variant is the comparator group and Booster Cohort:- mRNA:AZD2816 with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: 28 days after second dose (Day 57)

  50. GMT of SARS-CoV-2 nAb Against the B.1.351 Variant and the Original Wuhan-Hu-1 Strain by Booster Cohort:- mRNA:AZD1222

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Booster Cohort:- mRNA:AZD1222 with response against B.1.351 variant is the comparator group and Booster Cohort:- mRNA:AZD1222 with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: 28 days after second dose (Day 57)

  51. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against the Original Wuhan-Hu-1 Strain Elicited by Booster Cohort:- mRNA:AZD1222 and AZD1222 in Historical Control

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Booster Cohort:- mRNA:AZD1222 is the comparator group and AZD1222 in Historical Control is the reference group, both compared for response against the original Wuhan-Hu-1 strain.

    Measured: Booster Cohort: 28 days after booster dose (Day 29) and Historical Control: 28 days after the second dose (Day 57)

  52. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Booster Cohort:- mRNA:AZD1222 and Primary Vaccination Cohort:- AZD1222 (4)

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Booster Cohort:- mRNA:AZD1222 is the comparator group and Primary Vaccination Cohort:- AZD1222 (4) is the reference group, both compared for response against B.1.351 Variant.

    Measured: Booster Cohort: 28 days after booster dose (Day 29) and Primary Vaccination Cohort: 28 days after the second dose (Day 57)

  53. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Booster Cohort:- mRNA:AZD1222 and the Original Wuhan-Hu-1 Strain Elicited by AZD1222 in Historical Control

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Booster Cohort:- mRNA:AZD1222 with response against B.1.351 variant is the comparator group and AZD1222 in Historical Control with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: Booster Cohort: 28 days after booster dose (Day 29) and Historical Control: 28 days after the second dose (Day 57)

  54. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against B.1.351 Variant and the Original Wuhan-Hu-1 Strain Elicited by Booster Cohort:- mRNA:AZD2816

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Booster Cohort:- mRNA:AZD2816 with response against B.1.351 variant is the comparator group and Booster Cohort:- mRNA:AZD2816 with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: 28 days after second dose (Day 57)

  55. Percentage of Participants With Seroresponse of SARS-CoV-2 nAb Against B.1.351 Variant and the Original Wuhan-Hu-1 Strain Elicited by Booster Cohort:- mRNA:AZD1222

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline. Booster Cohort:- mRNA:AZD1222 with response against B.1.351 variant is the comparator group and Booster Cohort:- mRNA:AZD1222 with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: 28 days after second dose (Day 57)

  56. GMT of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Primary Vaccination Cohort:- AZD2816 (4) and the Original Wuhan-Hu-1 Strain Elicited by Primary Vaccination Cohort:- AZD1222 (4) on Day 29

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Primary Vaccination Cohort:- AZD2816 (4) with response against B.1.351 variant is the comparator group and Primary Vaccination Cohort:- AZD1222 (4) with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: 28 days after first dose (Day 29)

  57. GMT of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Primary Vaccination Cohort:- AZD2816 (4) and Primary Vaccination Cohort:- AZD1222 (4) on Day 29

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Primary Vaccination Cohort:- AZD2816 (4) is the comparator group and Primary Vaccination Cohort:- AZD1222 (4) is the reference group, both compared for response against B.1.351 variant.

    Measured: 28 days after first dose (Day 29)

  58. GMT of SARS-CoV-2 nAb Against B.1.351 Variant Elicited by Primary Vaccination Cohort:- AZD1222 + AZD2816 (4) and the Original Wuhan-Hu-1 Strain Elicited by Primary Vaccination Cohort:- AZD1222 (4) on Day 29

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Primary Vaccination Cohort:- AZD1222 + AZD2816 (4) with response against B.1.351 variant is the comparator group and Primary Vaccination Cohort:- AZD1222 (4) with response against the original Wuhan-Hu-1 strain is the reference group.

    Measured: 28 days after first dose (Day 29)

  59. GMT of SARS-CoV-2 nAb Against the Original Wuhan-Hu-1 Strain Elicited by Primary Vaccination Cohort:- AZD2816 (4) and Primary Vaccination Cohort:- AZD1222 (4) on Day 29

    Severe acute respiratory syndrome-coronavirus-2 nAb were measured by pseudoneutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information. Primary Vaccination Cohort:- AZD2816 (4) is the comparator group and Primary Vaccination Cohort:- AZD1222 (4) is the reference group, both compared for response against the original Wuhan-Hu-1 strain.

    Measured: 28 days after first dose (Day 29)

  60. GMT of ChAdOx1 nAb in Primary Vaccination Cohorts and Following a Booster Dose of AZD2816

    Chimpanzee adenovirus Ox1 (ChAdOx1) vector nAb were measured by neutralisation assay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information.

    Measured: Booster Cohorts: 28 days after booster dose (Day 29) and Primary Vaccination Cohorts: 28 days after the second dose (Day 57 for 4-week dosing interval cohorts and Day 113 for 12-week dosing interval cohort)

  61. Percentage of Participants With Seroresponse of ChAdOx1 nAb in Primary Vaccination Cohorts and Following a Booster Dose of AZD2816

    Chimpanzee adenovirus Ox1 vector nAb were measured by neutralisation assay. Seroresponse was defined as >= 4-fold increase in the GMT of nAb from baseline.

    Measured: Booster Cohorts: 28 days after booster dose (Day 29) and Primary Vaccination Cohorts: 28 days after the second dose (Day 57 for 4-week dosing interval cohorts and Day 113 for 12-week dosing interval cohort)

  62. GMT of SARS-CoV-2 Spike Protein Binding Antibodies in Primary Vaccination Cohorts and Booster Cohorts

    Severe acute respiratory syndrome-coronavirus-2 spike protein binding antibodies were measured by multiplexed immunoassay. The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titre/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titre, where 'n' was the number of participants with titre information.

    Measured: Booster Cohorts: 28 days after booster dose (Day 29) and Primary Vaccination Cohorts: 28 days after the second dose (Day 57 for 4-week dosing interval cohorts and Day 113 for 12-week dosing interval cohort)

  63. Percentage of Participants With Seroresponse of SARS-CoV-2 Spike Protein Binding Antibodies in Primary Vaccination Cohorts and Booster Cohorts

    Severe acute respiratory syndrome-coronavirus-2 spike protein binding antibodies were measured by multiplexed immunoassay. Seroresponse was defined as >= 4-fold increase in the GMT of spike protein binding antibodies from baseline.

    Measured: Booster Cohorts: 28 days after booster dose (Day 29) and Primary Vaccination Cohorts: 28 days after the second dose (Day 57 for 4-week dosing interval cohorts and Day 113 for 12-week dosing interval cohort)

  64. Correlation Between ChAdOx1 nAb and SARS-CoV-2 nAb Titres

    Severe acute respiratory syndrome-coronavirus-2 nAb and ChAdOx1 vector nAb were measured by pseudoneutralisation assay. Correlations were based on log2 titre values and assessed by using Spearman rank correlation for all cohorts except Primary Vaccination Cohort:- AZD2816 (12) for which Pearson correlation was used. The correlation coefficient is reported in values from +1 to -1 (+1= perfect association, 0 = no association, and -1= perfect negative association). The closer the correlation coefficient is to zero, weaker the association.

    Measured: Booster Cohorts: 28 days after booster dose (Day 29) and Primary Vaccination Cohorts: 28 days after the second dose (Day 57 for 4-week dosing interval cohorts and Day 113 for 12-week dosing interval cohort)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted22 Jul 2021
  2. Study start27 Jun 2021
  3. Primary completion4 Feb 2022
  4. Study completion2 Aug 2022

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2/3
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Model description
Previously vaccinated individuals will receive 1 dose of AZD1222 or AZD2816 on Day 1. Previously unvaccinated participants will receive one of the following 2-dose vaccinations: * 1 dose of AZD2816 on Day 1 and on Day 29 * 1 dose of AZD1222 on Day1 and on Day 29 * 1 dose of AZD1222 on Day 1 and 1 dose of AZD2816 on Day 29 * 1 dose of AZD2816 on Day 1 and on Day 85. Participants will be followed up for safety for 180 days after last study vaccine administration.
Masking
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
2,843 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04973449
Sponsor's protocol ID
D7220C00001
Other IDs
2021-002530-17
Acronym
AZD2816
Status last verified
Apr 2024
First submitted
2 Jul 2021
Last updated
19 Sep 2024
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: Qualified researchers can request access to anonymized individual patient-level data from AstraZeneca group of companies sponsored clinical trials via the request portal. All request will be evaluated as per the AZ disclosure commitment: https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure

Publications

  • Costa Clemens SA, Jepson B, Bhorat QE, Ahmad A, Akhund T, Aley PK, Bansal H, Bibi S, Kelly EJ, Khan M, Lambe T, Lombaard JJ, Matthews S, Pipolo Milan E, Olsson U, Ramasamy MN, Moura de Oliveira Paiva MS, Seegobin S, Shoemaker K, Szylak A, Villafana T, Pollard AJ, Green JA; AZD2816 Study Group. Immunogenicity and safety of beta variant COVID-19 vaccine AZD2816 and AZD1222 (ChAdOx1 nCoV-19) as primary-series vaccination for previously unvaccinated adults in Brazil, South Africa, Poland, and the UK: a randomised, partly double-blinded, phase 2/3 non-inferiority immunobridging study. Lancet Microbe. 2024 Aug;5(8):100863. doi: 10.1016/S2666-5247(24)00078-8. Epub 2024 Jun 12.

    PubMed 38878794

  • Ramasamy MN, Kelly EJ, Seegobin S, Dargan PI, Payne R, Libri V, Adam M, Aley PK, Martinez-Alier N, Church A, Jepson B, Khan M, Matthews S, Townsend GT, Vekemans J, Bibi S, Swanson PA 2nd, Lambe T, Pangalos MN, Villafana T, Pollard AJ, Green JA; AZD2816 Study Group. Immunogenicity and safety of AZD2816, a beta (B.1.351) variant COVID-19 vaccine, and AZD1222 (ChAdOx1 nCoV-19) as third-dose boosters for previously vaccinated adults: a multicentre, randomised, partly double-blinded, phase 2/3 non-inferiority immunobridging study in the UK and Poland. Lancet Microbe. 2023 Nov;4(11):e863-e874. doi: 10.1016/S2666-5247(23)00177-5. Epub 2023 Sep 29.

    PubMed 37783221

Questions about this trial

What is this clinical trial studying?

A Phase 2/3 study testing AZD1222 and AZD2816 in people with COVID-19 and SARS-CoV-2, run by AstraZeneca at 35 sites in 4 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 10 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 19 Sep 2024. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 35 sites in United Kingdom, Brazil, South Africa, Poland. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this combined phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 19 Sep 2024). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Number of Participants With Local and Systemic Solicited Treatment Emergent Adverse Events (TEAEs) in Primary Vaccination Cohort (PVC):- AZD2816 (4), Booster Cohorts:-AZD1222:AZD2816, and mRNA:AZD2816 (time frame: During the 7-day follow-up period after vaccination (vaccines administered on Days 1 and 29 [only for primary vaccination cohort])). The study lists 7 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04973449, which also lists 2 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Sep 2024.

AzTrials uses cookies for analytics and advertising. You can accept or reject them; the site works either way. Privacy Policy.

Free account

Log in to keep searching

You’ve used your 3 free searches. AzTrials is free: log in or create a free account to keep searching clinical trials and save the ones you want to follow.

Create a free accountLog in