NCT05142488

Study of Immunogenicity Equivalence of a Homologous Third Dose of Covid-19 (Recombinante) Vaccine

Study of Immunogenicity Equivalence After a Homologous Third Dose of Covid-19 (Recombinante) Vaccine, 6 Months After the Second Dose, Comparing Intervals of 8 and 12 Weeks Between the First Two Doses.

• Status: Unknown
• Phase: Phase 4
• Study type: Interventional
• Enrollment: 662 (estimated)
• Sponsor: The Immunobiological Technology Institute (Bio-Manguinhos) / Oswaldo Cruz Foundation (Fiocruz) · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Accepted

Summary

The purpose of this study is to evaluate the antibody response, safety and reactogenicity of a third dose Covid-19 (recombinante) vaccine, 6 months after a two-dose vaccine schedule using the same vaccine in all doses.

Detailed description

After being informed about the study and potential risks, all participants giving written informed consent will be evaluated for eligibility criteria. At day 0, participants who meet the eligibility requirements will undergo a thorough medical evaluation and a urine pregnancy test (if applicable). Previous vaccination information will be collected with the participant and checked via digital Covid-19 vaccine certification from the Brazilian public health national immunization program system (SI-PNI) ou from Fundação Oswaldo Cruz (Fiocruz) institutional occupational medicine data. According to the data collected, participants will be placed in one of two groups: 8 or 12 weeks interval between the first two vaccine doses in the vaccine schedule. Eligible and consenting participants will have a blood sample collected and receive immediately after a third dose of the Covid-19 (recombinante) vaccine. Participants will be instructed to fill out an adverse events journal for solicited adverse events for 7 days and non-solicited adverse events for 28 days after the third dose. The research team will contact the participant remotely at least once during the first two weeks. The participant will return for a follow-up visit to the research center 28 days after the third dose, to evaluate adverse events, collect a second blood sample and undergo a thorough medical evaluation. The participant will return to the research center to collect blood samples in three more follow-up visits: 3 months, 6 months and 12 months after the third dose.

Conditions

• COVID-19

Interventions

Type	Name	Description
BIOLOGICAL	Covid -19 (recombinante) vaccine	Third dose of the Covid-19 (recombinante) vaccine, 6 months after the second dose of a two dose Covid-19 (recombinante) homologous vaccine schedule.

Timeline

• Start date: 2021-11-09
• Primary completion: 2022-03-30
• Completion: 2023-03-30
• First posted: 2021-12-02
• Last updated: 2021-12-02

Locations

1 site across 1 country: Brazil