Immune Response of an Interchangeable Booster Vaccine Against COVID-19 Among Individuals With Risk Factors for Severity — COVACManaus2  

Healthy Clinical Trial

Official title: The Effects of the Interchangeability of the Booster Vaccine Against COVID-19 on the Immune Response Among Education and Public Safety Workers With Risk Factors for Severity, in Manaus (Amazonas)

Status Active, not recruiting

Clinical Trial Summary

Experimental, single-arm study in participants with comorbidities, previously immunized with 2 doses of CoronaVac, who will receive a booster vaccine with 1 dose of the Oxford/AstraZeneca vaccine.

Clinical Trial Description

Intervention: Oxford/AstraZeneca - 0.5 mL single dose, intramuscular in deltoid, with an interval of 180 days (+/- 30 days) from the 2nd dose of the initial vaccination schedule with CoronaVac

Inclusion criteria:

• Have voluntarily participated and be in regular follow-up monitoring by the COVACMANAUS study;

• Have completed the vaccination schedule with 2 doses of CoronaVac, as per the COVACMANAUS study protocol for at least 180 days (+/- 30 days);

• Demonstrate availability to be followed during the follow-up period defined in the study, through visits, telephone contacts or other digital means of communication;

• Accept to participate in this new study for 6 (six) months.

Exclusion criteria

• Confirmed diagnosis of COVID-19 within the last 28 days (antigen test or RT-PCR). In this situation, vaccination can be postponed until the participant completes 30 days;

• Report of fever within 72 hours prior to vaccination (inclusion can be postponed until the participant completes 72 hours without fever and COVID-19 is discarded);

• Having received live attenuated virus vaccine in the last 28 days or inactivated vaccine in the last 14 days prior to inclusion in the study;

• Any other condition that, in the opinion of the Principal Investigator or its medical representative, could jeopardize the safety or rights of a potential participant or prevent them from complying with this protocol;

• Pregnancy or lactation.

Type of study/study design: Experimental, single-arm study in participants with comorbidities, previously immunized with 2 doses of CoronaVac, who will receive a booster vaccine with 1 dose of the Oxford/AstraZeneca vaccine.

Sample size: all active participants from the COVACManaus study (up to 5071)

Primary outcome: Detection and titration of antibodies against SARS-CoV-2 before (D0), at D90 and D180 after booster vaccination

Secondary outcomes:

• Profile of the cell-mediated immune response in a subgroup of participants, before (D0), at D90 and D180 after booster vaccination;

• Ability to neutralize antibodies in a subgroup of participants before (D0), in D90 and D180 after the vaccine booster;

• Memory cell populations in a subgroup of participants before (D0), in D90 and D180 after booster vaccination.

• Detection and titration of antibodies against SARS-CoV-2 and its association with the history of physical activity or sedentary lifestyle. ;

Related Conditions & MeSH terms

• Comorbidities and Coexisting Conditions
• COVID-19
• Healthy

• NCT number: NCT05289206
• Study type: Interventional
• Source: Fundação de Medicina Tropical Dr. Heitor Vieira Dourado
• Status: Active, not recruiting
• Phase: N/A
• Start date: September 30, 2021
• Completion date: May 30, 2022