Covid-19
Conditions
Interventions
Sponsors
Eligibility
Inclusion criteria
Inclusion criteria: Participants in study RHH 001 per protocol population who were fully evaluable. Those participants included in previous neutralization assay subsets will be targeted for enrolment first if operationally feasible; Subjects willing and able to provide informed consent prior to any study procedure; Participants willing and able to comply with the study procedure; Subjects who had received heterologous or homologous third vaccine dose 6 months or more prior to this study. For part 2 in addition: nformed consent to receive 4 th vaccine dose, AstraZeneca/Fiocruz or Pfizer/Wyeth; No contraindication against AstraZeneca/ Fiocruz or Pfizer/ Wyeth SARSC0V2 vaccine; For females of childbearing potential: willingness to practice continuous effective contraception during the study and a negative pregnancy test on the days on day of vaccination.
Exclusion criteria
Exclusion criteria: Any additional SARSCoV2 vaccine after the 3rd dose in study RHH 001. For part 2 in addition: Participants with a history of serious vaccine-related adverse reaction or serious allergic reaction (e.g., anaphylaxis) to any study vaccine component, as described in the last summary of product characteristics for AstraZeneca/Fiocruz or Pfizer/Wyeth; Participants with a known bleeding disorder that, in the investigator’s opinion, would contraindicate intramuscular injection; Participants with any progressive or serious neurological disorder, seizure disorder or history of Guillian-Barré syndrome; Participants given treatment with immunosuppressant therapy within the last 90 days, including cytotoxic agents or systemic corticosteroids or planned receipt during the study period. If a short-term cycle of immunosuppressant systemic corticosteroid dose has been used to treat acute disease, the participant should not be enrolled in the study until corticosteroid therapy has been discontinued for at least 15 days prior to the first study vaccination. In case the participant has been on an immunosuppressant dose of a depot, intramuscular or intra-articular corticosteroid, 60 days should be waited for their enrolment in the study. Inhaled/nebulized, intra-articular, intrabursal or topical (skin or eyes) corticosteroids are allowed; Participants with autoimmune diseases, other than: Hashimoto thyroiditis, vitiligo, psoriasis, discoid lupus and the like; HIV positive participants and/or in treatment for HIV; Participants given any other investigational product within the 30 days prior to administration of 4th dose or who intend to take part in another clinical trial at any time during this study conduction; Participants given any other licensed vaccine within 14 days prior to enrolment in this study or who plan to receive any vaccine up to 28 days after vaccination; Participants given treatment with Rituximab or any other anti CD20 monoclonal antibody within 9 months prior to administration of 4 th dose or planned during the study period; Administration of intravenous immunoglobulins and/or any blood products within 3 months prior to enrolment or planned dosing during the study period; Participants with any condition that, in the investigator’s opinion, could interfere with the status primary objectives or represent an additional risk for the participant. Temporary exclusion criteria for both Part 1 and Part 2: Participants with a recent history of COVID19 (minor 4 weeks prior to visit 1) will be delayed until 4 weeks after diagnosis; Participants with fever major 37.5 °C (axillary) or any acute disease at baseline (Day 1) or within the 3 days prior to randomization. Febrile participants with mild diseases may be enrolled at the investigator’s discretion once fever has resolved.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| To assess the persistence of the humoral immune response of a homologous or heterologous booster regimen (third dose) in subjects previously vaccinated with two Sinovac/Butantan doses, overall and stratified by age as per the previous study (18 to 60 and more than 60 years old): Group 1: (N up to 272) Sinovac/Butantan (homologous); Group 2: (N up to 288) AstraZeneca/Fiocruz (heterologous); Group 3: (N up to 323) Pfizer/Wyeth (heterologous); Group 4: (N up to 285) Janssen (heterologous).;To assess non inferiority 28 days after a 4th dose of AstraZeneca/Fiocruz vaccine compared with 28 days after a 3rd dose of AstraZeneca/Fiocruz vaccine in the RHH 001 study. | — |
Secondary
| Measure | Time frame |
|---|---|
| To assess the persistence of a neutralizing immune response of a homologous or heterologous booster regimen (third dose) against wild-type strain, overall and age stratified (18 to 60 and more than 60 years old) in the subset of individuals from whom post dose 3 neutralizing data are available in study RHH 001.;To assess the persistence of a neutralizing immune response of a homologous or heterologous booster dose regimen (third dose) in subjects previously immunized with Sinovac/Butantan (2 doses) against wild-type strain and against variants.;To compare homologous versus heterologous response after a 4th dose of AstraZeneca/Fiocruz in participants that have previously received a 3rd dose booster in RHH 001.;To compare homologous versus heterologous anti-spike IgG response after a 4th dose of Pfizer/Wyeth in participants that have previously received a 3rd dose booster in RHH 001. ;To assess the persistence of antibody at 6 months after 4th dose of AstraZeneca/Fiocruz vaccine.;To assess antibody persistence 6 months after the 4th dose of Pfizer/Wyeth vaccine by titrating SARSCoV2 anti-Spike IgG antibodies 6 months after the fourth dose.;To assess the reactogenicity and safety of the fourth dose of vaccine by the occurrence of reported local and systemic Adverse Events within 7 days to 6 months after study vaccination (by subgroup). | — |
Countries
Brazil
Contacts
Instituto D'Or de Pesquisa e Ensino