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 studyis to measure vaccine effectiveness of homologous booster-dose vaccination withCoronaVac® against laboratory-confirmed symptomatic disease.
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):
1. VACIVIDA, comprising individual data for people vaccinated against SARS-Cov-2.
2. E-SUS, mandatory report database for mild to moderate COVID-19.
3. 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.
Biological: COVID-19 Vaccine (Vero Cell), Inactivated
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.
Other Name: CoronaVac®
Inclusion Criteria:
- 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.
Exclusion Criteria:
- 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.
Instituto Nacional de Infectologia Evandro Chagas (INI-FIOCRUZ)
Manguinhos, Brazil
André Machado amsiqueira@gmail.com, Doctor, Principal Investigator
amsiqueira@gmail.com