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Malaria, VivaxPhase 2NCT04009096

VAC071: A Study to Assess Efficacy of the ChAd63/MVA PvDBP Vaccines

A Phase 2 study testing ChAd63 PvDBP and MVA PvDBP in people with Malaria, Vivax, run by University of Oxford at 1 site in United Kingdom.

Completed

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

Official record
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Trial summary

This is an open label, Phase IIa, controlled human malaria infection (CHMI) study aimed to assess whether the new vivax malaria vaccines ChAd63 PvDBP and MVA PvDBP can protect against malaria infection. The participants will receive one or two doses of ChAd63 PvDBP followed by one dose of MVA PvDBP 8 weeks later. Read more about this study

Who is it for?
Ages 18 to 45 yearsHealthy volunteers can take part
Conditions the study is for
Malaria, Vivax
What is being tested?
ChAd63 PvDBP and MVA PvDBP
Type of treatment
Vaccines
Could I receive a placebo?
No, everyone receives an active treatment
How many people
16 participants
Where
1 siteUnited Kingdom
Study dates
18 Jul 2019to 7 Jul 2022
Phase
Phase 2
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 45 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Healthy adult aged 18 to 45 years.
  • Red blood cells positive for the Duffy antigen/chemokine receptor (DARC).
  • Normal serum levels of Glucose-6-phosphate dehydrogenase (G6PD).
  • Able and willing (in the Investigator's opinion) to comply with all study requirements.
  • Willing to allow the Investigators to discuss the volunteer's medical history with their General Practitioner.
  • Women only: Must practice continuous effective contraception* for the duration of the study
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  • Agreement to permanently refrain from blood donation
  • Written informed consent to participate in the trial.
  • Reachable (24/7) by mobile phone during the period between CHMI and completion of all antimalarial treatment.
  • Willing to take a curative anti-malarial regimen following CHMI.
  • Willing to reside in Oxford for the duration of the study, until antimalarials have been completed.
  • Answer all questions on the informed consent quiz correctly.
  • Female volunteers are required to use an effective form of contraception during the course of the study as malaria challenge could pose a serious risk to both maternal health and the unborn foetus.

Who cannot join

  • History of clinical malaria (any species).
  • Travel to a clearly malaria endemic locality during the study period or within the preceding six months.
  • Current or planned treatment with long-acting immune-modifying drugs at any time during the study period (e.g. infliximab).
  • Chronic use of antibiotics with antimalarial effects (e.g. tetracyclines for dermatologic patients, trimethoprim-sulfamethoxazole for recurrent urinary tract infections, etc.).
  • Weight less than 50kg, as measured at the screening visit.
  • Receipt of immunoglobulins within the three months prior to planned administration of the vaccine candidate.
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  • Receipt of blood products (e.g., blood transfusion) at any time in the past.
  • Peripheral venous access unlikely to allow twice daily blood testing (as determined by the Investigator).
  • Receipt of an investigational product in the 30 days preceding enrolment, or planned receipt during the study period.
  • Receipt of any vaccine in the 30 days preceding enrolment, or planned receipt of any other vaccine within 30 days preceding or following each study vaccination, with the exception of licensed COVID-19 vaccines, which should not be received within 14 days before or 7 days after any study vaccination.
  • Planned receipt of a COVID-19 vaccine between 2 weeks before the day of CHMI until completion of antimalarial treatment
  • Concurrent involvement in another clinical trial or planned involvement during the study period.
  • Prior receipt of an investigational vaccine likely to impact on interpretation of the trial data or the P. vivax parasite as assessed by the Investigator.
  • History of sickle cell anaemia, sickle cell trait, thalassaemia or thalassaemia trait or any haematological condition that could affect susceptibility to malaria infection.
  • Any confirmed or suspected immunosuppressive or immunodeficient state, including HIV infection; asplenia; recurrent, severe infections and chronic (more than 14 days) immunosuppressant medication within the past 6 months (inhaled and topical steroids are allowed).
  • History of allergic disease or reactions likely to be exacerbated by any component of the vaccine e.g. egg products, Kathon, aminoglycosides.
  • History of allergic disease or reactions likely to be exacerbated by malaria infection.
  • History of clinically significant contact dermatitis.
  • Any history of anaphylaxis in reaction to vaccinations.
  • Pregnancy, lactation or intention to become pregnant during the study.
  • Use of medications known to cause prolongation of the QT interval and existing contraindication to the use of Malarone.
  • Use of medications known to have a potentially clinically significant interaction with Riamet and Malarone.
  • Any clinical condition known to prolong the QT interval.
  • History of cardiac arrhythmia, including clinically relevant bradycardia.
  • Disturbances of electrolyte balance, e.g. hypokalaemia or hypomagnesaemia.
  • Family history of congenital QT prolongation or sudden death.
  • Contraindications to the use of both of the proposed anti-malarial medications; Riamet Malarone.
  • History of cancer (except basal cell carcinoma of the skin and cervical carcinoma in situ).
  • History of serious psychiatric condition that may affect participation in the study.
  • Any other serious chronic illness requiring hospital specialist supervision.
  • Suspected or known current alcohol abuse as defined by an alcohol intake of greater than 25 standard UK units every week.
  • Suspected or known injecting drug abuse in the 5 years preceding enrolment.
  • Hepatitis B surface antigen (HBsAg) detected in serum.
  • Seropositive for hepatitis C virus (antibodies to HCV) at screening or (unless has taken part in a prior hepatitis C vaccine study with confirmed negative HCV antibodies prior to participation in that study, and negative HCV RNA PCR at screening for this study).
  • Positive family history in both 1st AND 2nd degree relatives < 50 years old for cardiac disease.
  • Volunteers unable to be closely followed for social, geographic or psychological reasons.
  • Any clinically significant abnormal finding on biochemistry or haematology blood tests, urinalysis or clinical examination. In the event of abnormal test results, confirmatory repeat tests will be requested. Procedures for identifying laboratory values meeting exclusion criteria are shown in SOP VC027.
  • Any other significant disease, disorder, or finding which may significantly increase the risk to the volunteer because of participation in the study, affect the ability of the volunteer to participate in the study or impair interpretation of the study data.
  • Inability of the study team to contact the volunteer's GP to confirm medical history and safety to participate.

Trial locations and contacts

1 site in 1 country.

United Kingdom1 site
  • Centre for Clinical Vaccinology & Tropical Medicine

    Oxford, Oxfordshire, OX3 7LE

Other trials in United Kingdom

About this study

Official title: A Phase IIa Challenge Study to Assess Efficacy of the Plasmodium Vivax Malaria Vaccine Candidates ChAd63 PvDBP and MVA PvDBP in Healthy Adults Living in the UK

This is an open label, Phase IIa, controlled human malaria infection (CHMI) study aimed to assess whether the new vivax malaria vaccines ChAd63 PvDBP and MVA PvDBP can protect against malaria infection.

The participants will receive one or two doses of ChAd63 PvDBP followed by one dose of MVA PvDBP 8 weeks later.

Approximately 4 weeks after the second vacccination, the volunteers will be challenged (deliberately infected) with malaria by intravenous injection blood-stage

Read the detailed description

Volunteers will be recruited and vaccinated at the CCVTM, Oxford.

There will be two groups vaccinated in the trial, with an optional third group included if fewer than 6 volunteers complete group 2. Up to 19 volunteers will be included in total. These will be compared to a matched number of infectivity controls, receiving no vaccination, who will be recruited as part of a separate study (VAC069 - NCT03797989).

Conditions
Malaria, Vivax
Being tested
ChAd63 PvDBP and MVA PvDBP
Keywords
PvDBP, efficacy
Medical subject headings
Malaria, Vivax

What participants receive

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

  • ChAd63 PvDBP and MVA PvDBPBiological

    one dose of 5 x 10^10 vp ChAd63 PvDBP and one dose of 2 x 10^8 pfu MVA PvDBP 8 weeks later, in a heterologous prime-boost regimen.

Study groups in NCT04009096
Study groupRoleWhat they receive
Group 1Experimental3 volunteers receiving 5 x 10^10 vp ChAd63 PvDBP and 2 x 10^8 pfu MVA PvDBP 8 weeks later, in a heterologous prime-boost regimen, followed by blood-stage CHMI 2-4 weeks later.
Receives: Biological: ChAd63 PvDBP and MVA PvDBP
Group 2ExperimentalUp to 10 volunteers receiving one dose of 5 x 10^10 vp ChAd63 PvDBP, 12-18 months later receiving a second dose of 5 x 10^10 vp ChAd63 PvDBP and 8 weeks later 2 x 10^8 pfu MVA PvDBP, followed by blood-stage CHMI 2-4 weeks later.
Receives: Biological: ChAd63 PvDBP and MVA PvDBP
Group 3ExperimentalIf fewer than 6 volunteers complete the study in Group 2, then new volunteers will be recruited into Group 3, to make up a total of 6 volunteers between Groups 2 and 3 who complete all vaccinations and CHMI. Volunteers in Group 3 will receive 5 x 10^10 vp ChAd63 PvDBP and 2 x10^8 pfu MVA PvDBP 8 weeks later, in a heterologous prime-boost regimen, followed by blood-stage CHMI 2-4 weeks later.
Receives: Biological: ChAd63 PvDBP and MVA PvDBP

What is being measured

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

  1. Efficacy of the ChAd63 and MVA PvDBP Vaccines, Administered in a Heterologous Prime-boost Regimen, Assessed by a Reduced Parasite Multiplication Rate in Vaccinated Subjects

    Quantitative PCR-derived parasite multiplication rate (PMR) will be the primary efficacy endpoint and a comparison of the endpoint between Groups 1, 2 and 3 (pooled data) and malaria-naïve controls partaking in simultaneous CHMI, under identical conditions, will constitute the primary analysis for efficacy.

    Measured: 3 months post CHMI

Secondary outcomes (4)
  1. Safety of the ChAd63 and MVA PvDBP Vaccines Andidates, Administered in a Heterologous Prime-boost Regimen in a CHMI Study in Healthy Volunteers

    No of participants reporting adverse event

    Measured: Within 28 days following each vaccination. Vaccinations occurred at 0 and 2 months in Groups 1 and 3 (ChAd63, MVA PvDBP); and at 0, 17 and 19 months in Group 2 (ChAd63, ChAd63, MVA PvDBP).

  2. The Humoral Immunogenicity ChAd63 and MVA PvDBP Vaccine Candidates, Administered in a Heterologous Prime-boost Regimen

    Total IgG antibody response to the P. vivax Duffy-binding protein (PvDBP)

    Measured: 14 days after the final vaccination. Final vaccinations (MVA PvDBP) occurred at 2 months in Groups 1 and 3; and at 19 months in Group 2.

  3. The Cellular Immunogenicity ChAd63 and MVA PvDBP Vaccine Candidates, Administered in a Heterologous Prime-boost Regimen

    PvDBPII-specific CD4+ CD45RA- CCR7- effector memory T cells producing IFN-γ

    Measured: 14 days after the final vaccination. Final vaccinations (MVA PvDBP) occurred at 2 months in Groups 1 and 3 ; and at 19 months in Group 2.

  4. Immunological Readouts for Association With a Reduced Parasite Multiplication Rate

    Statistical correlation between anti-PvDBP antibody responses induced by the ChAd63 and MVA PvDBP vaccines and PMR.

    Measured: 3 months post CHMI

Timeline

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

  1. First posted5 Jul 2019
  2. Study start18 Jul 2019
  3. Primary completion7 Jul 2022
  4. Study completion7 Jul 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
Primary purpose
Prevention
Allocation
Non-randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
16 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04009096
Sponsor's protocol ID
VAC071
Status last verified
Sep 2022
First submitted
3 Jul 2019
Last updated
12 Apr 2024
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No

Publications

  • Hou MM, Barrett JR, Themistocleous Y, Rawlinson TA, Diouf A, Martinez FJ, Nielsen CM, Lias AM, King LDW, Edwards NJ, Greenwood NM, Kingham L, Poulton ID, Khozoee B, Goh C, Mac Lochlainn DJ, Salkeld J, Guilotte-Blisnick M, Huon C, Mohring F, Reimer JM, Chauhan VS, Mukherjee P, Biswas S, Taylor IJ, Lawrie AM, Cho JS, Nugent FL, Long CA, Moon RW, Miura K, Silk SE, Chitnis CE, Minassian AM, Draper SJ. Impact of a blood-stage vaccine on Plasmodium vivax malaria. medRxiv [Preprint]. 2022 May 30:2022.05.27.22275375. doi: 10.1101/2022.05.27.22275375.

    PubMed 35664997

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing ChAd63 PvDBP and MVA PvDBP in people with Malaria, Vivax, run by University of Oxford at 1 site in United Kingdom.

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 13 inclusion and 39 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 12 Apr 2024. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United Kingdom. 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 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.

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 12 Apr 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?

Efficacy of the ChAd63 and MVA PvDBP Vaccines, Administered in a Heterologous Prime-boost Regimen, Assessed by a Reduced Parasite Multiplication Rate in Vaccinated Subjects (time frame: 3 months post CHMI). 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 NCT04009096, which also lists 1 linked publication.

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 12 Apr 2024; AzTrials last refreshed its copy on 7 Nov 2026.

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