Clinical trial NCT05367895: Effectiveness of Inactivated COVID-19 Vaccine of the First Booster Dose
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
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: COVID-19
Lead sponsor: Sinovac Biotech Co., Ltd
Sponsor class: INDUSTRY
First posted: 2022-05-10
Enrollment: 14000
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: CASE_CONTROL
Time perspective: RETROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
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.

Brief 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.

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):

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.

Eligibility criteria: 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.

Primary outcomes:
measure: Effectiveness of homologous booster-dose vaccination with CoronaVac®
timeFrame: 6 months after the third dose of COVID-19 vaccine
Secondary outcomes:
measure: effectiveness of homologous booster-dose vaccination with CoronaVac®
timeFrame: 6 months after the third dose of COVID-19 vaccine
measure: vaccine effectiveness of homologous booster-dose vaccination with CoronaVac®
timeFrame: 6 months after the third dose of COVID-19 vaccine
measure: Vaccine effectiveness of homologous booster-dose vaccination with CoronaVac®
timeFrame: 6 months after the third dose of COVID-19 vaccine
Other outcomes:
measure: vaccine effectiveness of homologous booster-dose vaccination
timeFrame: 6 months after the third dose of COVID-19 vaccine
measure: help support the approval of new indication (i.e. boosters) of the CoronaVac®.
timeFrame: 6 months after the third dose of COVID-19 vaccine
measure: support post-approval study requirements of CoronaVac®.
timeFrame: 6 months after the third dose of COVID-19 vaccine
Locations:
city: Manguinhos
country: Brazil
facility: Instituto Nacional de Infectologia Evandro Chagas (INI-FIOCRUZ)
Study officials:
affiliation: amsiqueira@gmail.com
name: André Machado amsiqueira@gmail.com, Doctor
role: PRINCIPAL_INVESTIGATOR
References: