Effectiveness of COVID-19 Vaccine for Prevention of COVID-19 in the Dominican Republic

Effectiveness of COVID-19 Vaccine (Vero Cell), Inactivated (CoronaVac) for Preventing Symptomatic SARS-CoV-2 Infections and Hospitalizations in the Dominican Republic - Test-Negative Case-Control Study

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT04974164

Enrollment

1400

Registered

2021-07-23

Start date

2021-08-17

Completion date

2021-12-13

Last updated

2022-08-23

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

COVID-19

Brief summary

This study is a multisite ,grouped test-negative case-control , phase Ⅳ clinical trial of an inactivated SARS-CoV-2 vaccine (CoronaVac) manufactured by Sinovac Research and Development Co., Ltd.The purpose of this study is to estimate the protective effectiveness of complete vaccination (measured ≥14 days after the second dose) of CoronaVac against symptomatic SARS-COV-2 infections ,COVID-19 hospitalizations and severe cases.

Detailed description

This study is a multisite,grouped test-negative case-control , phase Ⅳ clinical trial in population aged 18 years and older. The experimental vaccine will be manufactured by Sinovac Research and Development Co.,Ltd.The study is planned to be carried out in ten (10) selected hospitals and their catchment communities in five provinces of the Dominican Republic (DR): National District, La Altagracia, Puerto Plata, Santiago, and Santo Domingo from July 1, 2021 to April 30, 2022 . A total of 1400 subjects will be enrolled with 700 estimated clinic cases who are diagnosed as SARS-CoV-2 infection by real-time polymerase chain reaction (RT-PCR); and 700 estimated clinic controls who have a negative RT-PCR test.And subjects will receive two doses of vaccine for primary immunization .

Interventions

BIOLOGICALInactivated COVID-19 Vaccine

Each vial contains 0.5 mL (a single dose) and contains 600SU of inactivated SARS-CoV-2 virus antigen

Study design

Observational model

CASE_CONTROL

Time perspective

PROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Yes

Inclusion criteria

* Aged ≥18 years; * Permanent residents of study provinces; * Able and willing to provide informed consent to participate in the study; * Able and willing to provide nasopharyngeal swab and venous blood sample; * Able and willing to complete a questionnaire survey for collecting information on histories of COVID-19 vaccination and disease; * Considered as suspected cases of SARS-CoV-2 infections by the physicians in the study clinics according to DR national protocol.

Exclusion criteria

Design outcomes

Primary

Measure	Time frame	Description
Protective effectiveness of complete vaccination of CoronaVac against symptomatic SARS-COV-2 infections	Day 14 after the second dose	SARS-COV-2 infections confirmed by real-time polymerase chain reaction (RT-PCR) in newly collected nasopharyngeal swab sample among patients visiting the ER in the study hospitals during the study period without a positive RT-PCR test in the preceding 90 days period
Protective effectiveness of complete vaccination of CoronaVac against COVID-19 hospitalizations and severe cases.	Day 14 after the second dose	Severe disease (including death), defined as a score \>5 in terms of WHO clinical progression scale due to SARS-CoV-2 infection

Secondary

Measure	Time frame	Description
To profile the circulating strains of SARS-CoV-2 in DR	Day 14 after the second dose	Circulating strains of SARS-CoV-2 in DR

Countries

Dominican Republic

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026