Effectiveness of Inactivated COVID-19 Vaccine of the First Booster Dose

An observational study of COVID-19, run by Sinovac Research and Development Co., Ltd. at 1 site in Brazil.

Unknown status

Status not confirmed. The sponsor has not verified this record for over two years, so it may be out of date.

Trial summary

This is a retrospective test-negative case-control study of COVID-19 Vaccine (CoronaVac®) manufactured by Sinovac Research and Development Co., Ltd.The main purpose of this study is to measure vaccine effectiveness of homologous booster-dose vaccination with CoronaVac® against laboratory-confirmed symptomatic disease. Read more about this study

Who is it for?: Ages 18 years and olderHealthy volunteers can take part
Conditions the study is for: COVID-19
What is being tested?: COVID-19 Vaccine (Vero Cell), Inactivated
Type of treatment: Vaccines
How many people: 14,000 participants
Where: 1 siteBrazil
Study dates: 30 Jul 2022to 15 Feb 2023
Phase: Observational
Are there results?: None posted in the registry

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 years and older
All sexes
Healthy volunteers accepted
Adult, Older adult

Study population: The study population is community-dwelling individuals aged 18 years and above with no contra-indication for COVID-19 vaccination who consult a participating general practitioner or a hospital in São Paulo city, Brazil if they develop illness of interests (i.e., WHO definition of suspected COVID-19 cases) and had RT-PCR for SARS-Cov-2 colleceted.

Who may be able to join

Exposure group 1: Adults (≥ 18 years of age) registered in the E-SUS or SIVEP-gripe RWD source data from August 16th, 2021 through April 21st, 2022 and received a three-dose homologous vaccination with CoronaVac. Specifically, ≥14 days after receipt of the third vaccine dose using a homologous regimen with CoronaVac.
Exposure group 2: Adults (≥ 18 years of age) registered in the E-SUS or SIVEP-gripe RWD source data from August 16th, 2021 through April 21st, 2022, who received a two-dose vaccination with CoronaVac and did not receive any booster vaccine. Specifically, ≥14 days after receipt of the second vaccine dose and before the third dose of CoronaVac.
Exposure group 3: Adults (≥ 18 years of age) registered in the E-SUS or SIVEP-gripe RWD source data from August 16th, 2021 through April 21st, 2022, who received only one dose vaccination with CoronaVac and did not receive any other vaccine dose. Specifically, ≥14 days after receipt of the first vaccine dose and before the second dose of CoronaVac.
Non-Exposure group: Adults (≥ 18 years of age) registered in the E-SUS or SIVEP-gripe RWD source data from August 16th, 2021 through April 21st, 2022, who were not vaccinated. No history of vaccination for any type of COVID-19 vaccine, or <14 days after receipt of the first vaccine of CoronaVac.

Who cannot join

Anyone who received other vaccines for the first doses.
Anyone who received CoronaVac for the two initial doses but other vaccines for the booster (heterologous immunization).
Subjects with incomplete vaccination history.

Trial locations and contacts

1 site in 1 country.

Brazil1 site

Instituto Nacional de Infectologia Evandro Chagas (INI-FIOCRUZ)
Manguinhos

Other trials in Brazil

About this study

Official title: Effectiveness of CoronaVac® First Booster Dose for Preventing Symptomatic Acute Respiratory Infection Caused by SARS-CoV-2 Virus in Adults in São Paulo City, Brazil: a Retrospective Test-negative Case-control Study

Read the detailed description

This is a retrospective test-negative case-control study in São Paulo city, Brazil . The COVID-19 Vaccine (CoronaVac® )produced by Sinovac Research and Development Co., Ltd.The main purpose of this study is to measure vaccine effectiveness of homologous booster-dose vaccination with CoronaVac® against laboratory-confirmed symptomatic disease.A total of 14000 subjects will be enrolled,including 7,000 positive cases and 7,000 test negative COVID-19 cases The Statistical Analysis Plan (SAP) will include univariate (and, when required, multivariable) models of logistic regression.Data will be recovered from three health surveillance information electronic health records (EHRs):

VACIVIDA, comprising individual data for people vaccinated against SARS-Cov-2.
E-SUS, mandatory report database for mild to moderate COVID-19.
SIVEP-GRIPE, mandatory report database for severe cases of COVID-19. All those RWD sources are available at the São Paulo Municipality Centers for Health Surveillance.

Conditions: COVID-19
Being tested: COVID-19 Vaccine (Vero Cell), Inactivated
Medical subject headings: COVID-19

What participants receive

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

COVID-19 Vaccine (Vero Cell), InactivatedBiological
Also called CoronaVac®
Form: CoronaVac® is a milky-white suspension. Stratified precipitate may form that can be dispersed by shaking.
Presentation: Each vial contains 0.5 mL (a single dose) and contains 600SU of inactivated SARS-CoV-2 virus antigen.
Administration and schedule: Two doses with an interval of 21 days should be administered for primary immunization. 0.5 mL per dose.
Route: IM in the deltoid region of the upper arm after shaking the vial well before use.

Study groups in NCT05367895
Study group	Role	What they receive
Exposure group 1		Adults (≥ 18 years of age) registered in the E-SUS or SIVEP-gripe RWD source data from August 16th, 2021 through April 21st, 2022 and received a three-dose homologous vaccination with CoronaVac. Specifically, ≥14 days after receipt of the third vaccine dose using a homologous regimen with CoronaVac. Receives: Biological: COVID-19 Vaccine (Vero Cell), Inactivated
Exposure group 2		Adults (≥ 18 years of age) registered in the E-SUS or SIVEP-gripe RWD source data from August 16th, 2021 through April 21st, 2022, who received a two-dose vaccination with CoronaVac and did not receive any booster vaccine. Specifically, ≥14 days after receipt of the second vaccine dose and before the third dose of CoronaVac. Receives: Biological: COVID-19 Vaccine (Vero Cell), Inactivated
Exposure group 3		Adults (≥ 18 years of age) registered in the E-SUS or SIVEP-gripe RWD source data from August 16th, 2021 through April 21st, 2022, who received only one dose vaccination with CoronaVac and did not receive any other vaccine dose. Specifically, ≥14 days after receipt of the first vaccine dose and before the second dose of CoronaVac.
Non-Exposure group		Adults (≥ 18 years of age) registered in the E-SUS or SIVEP-gripe RWD source data from August 16th, 2021 through April 21st, 2022, who were not vaccinated. No history of vaccination for any type of COVID-19 vaccine, or <14 days after receipt of the first vaccine of CoronaVac. Receives: Biological: COVID-19 Vaccine (Vero Cell), Inactivated

What is being measured

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

Effectiveness of homologous booster-dose vaccination with CoronaVac®
To measure vaccine effectiveness of homologous booster-dose vaccination with CoronaVac® against laboratory-confirmed symptomatic disease
Measured: 6 months after the third dose of COVID-19 vaccine

Secondary outcomes (3)

effectiveness of homologous booster-dose vaccination with CoronaVac®
To measure vaccine effectiveness of homologous booster-dose vaccination with CoronaVac® against laboratory-confirmed COVID-19 hospital admissions
Measured: 6 months after the third dose of COVID-19 vaccine
vaccine effectiveness of homologous booster-dose vaccination with CoronaVac®
To measure vaccine effectiveness of homologous booster-dose vaccination with CoronaVac® against laboratory-confirmed COVID-19 intensive care unit admissions.
Measured: 6 months after the third dose of COVID-19 vaccine
Vaccine effectiveness of homologous booster-dose vaccination with CoronaVac®
To measure vaccine effectiveness of homologous booster-dose vaccination with CoronaVac® against laboratory-confirmed COVID-19 intensive care unit deaths.
Measured: 6 months after the third dose of COVID-19 vaccine

Timeline

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

30 Jul 202215 Feb 2023

First posted10 May 2022
Study start30 Jul 2022
Primary completion15 Aug 2022
Study completion15 Feb 2023 (estimated)

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Other trials for COVID-19Studies of the same condition, open and under way.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

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

Study design

Study type: Observational
Observational model: Case-control
Time perspective: Retrospective
Enrolment: 14,000 participants (estimated)

IDs, dates and publications

ClinicalTrials.gov ID: NCT05367895
Sponsor's protocol ID: EFFERVESCENCE/ BRAZIL
Status last verified: Apr 2022
First submitted: 28 Apr 2022
Last updated: 12 Jan 2023
Results posted: No
Data monitoring committee: No
FDA-regulated drug: No
FDA-regulated device: No

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

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All COVID-19 trials

Study at a glance

From the registry record, last updated by the sponsor on 12 Jan 2023. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: Effectiveness of CoronaVac® First Booster Dose for Preventing Symptomatic Acute Respiratory Infection Caused by SARS-CoV-2 Virus in Adults in São Paulo City, Brazil: a Retrospective Test-negative Case-control Study
ClinicalTrials.gov ID: NCT05367895
Acronym / sponsor ID: EFFERVESCENCE/ BRAZIL
Conditions: COVID-19
Study type: Observational
Recruitment status: Unknown status
Enrolment: 14,000 participants (estimated)
Lead sponsor: Sinovac Research and Development Co., Ltd.Industry (pharma, biotech, devices)
Study start: 30 Jul 2022 (actual)
Primary completion: 15 Aug 2022 (actual)
Study completion: 15 Feb 2023 (estimated)
First posted: 10 May 2022 (actual)
Results: Not posted in the source record

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Detailed description

VACIVIDA, comprising individual data for people vaccinated against SARS-Cov-2.
E-SUS, mandatory report database for mild to moderate COVID-19.
SIVEP-GRIPE, mandatory report database for severe cases of COVID-19. All those RWD sources are available at the São Paulo Municipality Centers for Health Surveillance.

Study design

Observational model: Case-control
Time perspective: Retrospective
Number of arms: 4

Arm	Type	Receives
Exposure group 1	–	Biological: COVID-19 Vaccine (Vero Cell), InactivatedAdults (≥ 18 years of age) registered in the E-SUS or SIVEP-gripe RWD source data from August 16th, 2021 through April 21st, 2022 and received a three-dose homologous vaccination with CoronaVac. Specifically, ≥14 days after receipt of the third vaccine dose using a homologous regimen with CoronaVac.
Exposure group 2	–	Biological: COVID-19 Vaccine (Vero Cell), InactivatedAdults (≥ 18 years of age) registered in the E-SUS or SIVEP-gripe RWD source data from August 16th, 2021 through April 21st, 2022, who received a two-dose vaccination with CoronaVac and did not receive any booster vaccine. Specifically, ≥14 days after receipt of the second vaccine dose and before the third dose of CoronaVac.
Exposure group 3	–	–Adults (≥ 18 years of age) registered in the E-SUS or SIVEP-gripe RWD source data from August 16th, 2021 through April 21st, 2022, who received only one dose vaccination with CoronaVac and did not receive any other vaccine dose. Specifically, ≥14 days after receipt of the first vaccine dose and before the second dose of CoronaVac.
Non-Exposure group	–	Biological: COVID-19 Vaccine (Vero Cell), InactivatedAdults (≥ 18 years of age) registered in the E-SUS or SIVEP-gripe RWD source data from August 16th, 2021 through April 21st, 2022, who were not vaccinated. No history of vaccination for any type of COVID-19 vaccine, or <14 days after receipt of the first vaccine of CoronaVac.

Who may qualify

Ages: 18 years and older
Sex: All
Healthy volunteers: Accepted
Age groups: Adult, Older adult
Study population: The study population is community-dwelling individuals aged 18 years and above with no contra-indication for COVID-19 vaccination who consult a participating general practitioner or a hospital in São Paulo city, Brazil if they develop illness of interests (i.e., WHO definition of suspected COVID-19 cases) and had RT-PCR for SARS-Cov-2 colleceted.

Key inclusion criteria (4 listed)

Exposure group 1: Adults (≥ 18 years of age) registered in the E-SUS or SIVEP-gripe RWD source data from August 16th, 2021 through April 21st, 2022 and received a three-dose homologous vaccination with CoronaVac. Specifically, ≥14 days after receipt of the third vaccine dose using a homologous regimen with CoronaVac.
Exposure group 2: Adults (≥ 18 years of age) registered in the E-SUS or SIVEP-gripe RWD source data from August 16th, 2021 through April 21st, 2022, who received a two-dose vaccination with CoronaVac and did not receive any booster vaccine. Specifically, ≥14 days after receipt of the second vaccine dose and before the third dose of CoronaVac.
Exposure group 3: Adults (≥ 18 years of age) registered in the E-SUS or SIVEP-gripe RWD source data from August 16th, 2021 through April 21st, 2022, who received only one dose vaccination with CoronaVac and did not receive any other vaccine dose. Specifically, ≥14 days after receipt of the first vaccine dose and before the second dose of CoronaVac.
Non-Exposure group: Adults (≥ 18 years of age) registered in the E-SUS or SIVEP-gripe RWD source data from August 16th, 2021 through April 21st, 2022, who were not vaccinated. No history of vaccination for any type of COVID-19 vaccine, or <14 days after receipt of the first vaccine of CoronaVac.

Key exclusion criteria (3 listed)

Anyone who received other vaccines for the first doses.
Anyone who received CoronaVac for the two initial doses but other vaccines for the booster (heterologous immunization).
Subjects with incomplete vaccination history.

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
COVID-19 Vaccine (Vero Cell), InactivatedAlso: CoronaVac®Form: CoronaVac® is a milky-white suspension. Stratified precipitate may form that can be dispersed by shaking. Presentation: Each vial contains 0.5 mL (a single dose) and contains 600SU of inactivated SARS-CoV-2 virus antigen. Administration and schedule: Two doses with an interval of 21 days should be administered for primary immunization. 0.5 mL per dose. Route: IM in the deltoid region of the upper arm after shaking the vial well before use.	Biological	Exposure group 1, Exposure group 2, Non-Exposure group

Primary outcome

Effectiveness of homologous booster-dose vaccination with CoronaVac®
Time frame: 6 months after the third dose of COVID-19 vaccine
To measure vaccine effectiveness of homologous booster-dose vaccination with CoronaVac® against laboratory-confirmed symptomatic disease

3 secondary outcomes

effectiveness of homologous booster-dose vaccination with CoronaVac®
Time frame: 6 months after the third dose of COVID-19 vaccine
vaccine effectiveness of homologous booster-dose vaccination with CoronaVac®
Time frame: 6 months after the third dose of COVID-19 vaccine
Vaccine effectiveness of homologous booster-dose vaccination with CoronaVac®
Time frame: 6 months after the third dose of COVID-19 vaccine

Results and safety

Results are not available in the source record.

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 12 Jan 2023.

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Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

André Machado amsiqueira@gmail.com, Doctor principal investigator

amsiqueira@gmail.com

1 site in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

An observational study of COVID-19, run by Sinovac Research and Development Co., Ltd. at 1 site in Brazil.

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 4 inclusion and 3 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: status not confirmed, as of the sponsor's last update on 12 Jan 2023. 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 Brazil. 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.

Are results available for this study?

Results are not available in the source record.

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?

Effectiveness of homologous booster-dose vaccination with CoronaVac® (time frame: 6 months after the third dose of COVID-19 vaccine). 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 NCT05367895.

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 Jan 2023.