A Clinical Study for Safety and Immunogenicity Increment after Extra Dose with Chadox1-S/NCOV-19 or third dose of Coronavac in previously Vaccinated Elderly subjects

A Randomized, Patient-Single-Blind Phase IV Clinical Study for Assessing the Safety and Laboratory Immunogenicity Increment after Vaccine Booster with Chadox1-S/NCOV-19 or third dose of Coronavac in previously Vaccinated Elderly subjects

Status

Active, not recruiting

Phases

Phase 4

Study type

Interventional

Source

REBEC

Registry ID

RBR-5d758t9

Enrollment

Unknown

Registered

2021-09-15

Start date

2021-09-18

Completion date

Unknown

Last updated

2025-10-27

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

Conditions

COVID-19 Infection

Interventions

A total of 300 male and female participants previously vaccinated with CoronaVac, aged 60 years or older, will be prospectively enrolled and randomized into the study.Participants will be randomized 2

Z24

Eligibility

Age

60 Years to No maximum

Inclusion criteria

Inclusion criteria: Male or female participants; aged 60 years or older; previously vaccinated with CoronaVac; Have previously received 2 doses of CoronaVac, as per the national immunization plan; the second dose administered at least 30 days ago.

Exclusion criteria

Exclusion criteria: Have had Covid-19 after the start of the vaccination schedule with CoronaVac; Symptoms of infection of any organ or etiology in the last 30 days, as per investigator’s judgment; Have had contact with an individual diagnosed with COVID-19 in the work or home environment in the last 10 days;Subjects with AIDS, severe immunosuppression or patients with a severe disease, as per investigator’s judgment.Have a Karnofsky Performance status below or lower than 70 (Attachment A). Known allergy to the components of the vaccines used in the study. Participation in another clinical study in less than 1 year (unless participation is justifiable as per the principal investigator).

Design outcomes

Primary

Measure	Time frame
To prove the neutralizing humoral immunogenicity increment provided with a third dose of CoronaVac compared to the same booster dose with the ChAdOx1-S/nCoV-19 vaccine in participants aged 60 years or older by serological analyses for total anti-S, anti-RBD, anti-N IgG and neutralization assay with live virus performed on the day of randomization and 30 days after vaccination	—

Secondary

Measure	Time frame
To compare the cellular immune response provided with a third dose of Coronavac compared to the same booster dose with the ChAdOx1-S/nCoV-19 vaccine in subjects aged 60 years or older by cellular response analyses in 50 random volunteers (25 of each group) and general immune marker characterization (T and B cells); To assess the safety of both vaccines, with special attention to post-vaccine adverse events by participant folow up on remote safety visits, planned to be performed on 7,14,21days after vaccination; on site visit 30 days after vacination; remote safety visits 15, 30, 45 days after on site visit, and final remote visit 90 days after on site visit.	—

Measure

Time frame

To compare the cellular immune response provided with a third dose of Coronavac compared to the same booster dose with the ChAdOx1-S/nCoV-19 vaccine in subjects aged 60 years or older by cellular response analyses in 50 random volunteers (25 of each group) and general immune marker characterization (T and B cells); To assess the safety of both vaccines, with special attention to post-vaccine adverse events by participant folow up on remote safety visits, planned to be performed on 7,14,21days after vaccination; on site visit 30 days after vacination; remote safety visits 15, 30, 45 days after on site visit, and final remote visit 90 days after on site visit.

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Countries

Brazil

Contacts

Public ContactDr. Bruno Filardi

bafilardi@gmail.com551640098140

Outcome results

None listed

Source: REBEC (via WHO ICTRP)