Effectiveness of the Oxford-AstraZeneca COVID-19 Vaccine as a 2nd Booster, the REFORCO-Brazil Study

NCT05697705 | Completed

• 1 other identifier: D8111R00028
• Study Type: observational
• Target: 188,814,085
• Locations: 1 country
• Sites: 1

Brief Summary

This study will address specific questions concerning the additional protection of the AZ COVID-19 vaccine as a second booster dose in preventing severe COVID-19 outcomes (hospitalisation, ICU admission etc) and will provide data to inform COVID-19 vaccine booster dose recommendations.

Conditions

COVID-19

Keywords

COVID-19, Real-World Effectiveness, ChAdOx1 nCOV-19 vaccine, Second booster dose

Outcome Measures

Primary Outcomes (1)

• COVID-19 confirmed by a positive antigen test or RT-PCR test in an individual hospitalized for SARS

  Study includes SARS hospitalizations between August 2021 and December 2022 for evaluation of 1st booster dose effectiveness, and SARS hospitalizations between January 2022 and December 2022 for evaluation of 2nd booster dose effectiveness.

  Sample date within 14 days prior to and up to 2 days after hospitalization.

Study Arms (2)

Population A

For evaluating second booster doses

Other: ChAdOx1 nCOV-19 vaccine (Vaxzeria); Other: BNT162b2 (Pfizer); Other: Ad26.COV2.S (Janssen); Other: CoronaVac (Sinovac)

Population B

For evaluating first booster doses

Other: ChAdOx1 nCOV-19 vaccine (Vaxzeria); Other: BNT162b2 (Pfizer); Other: Ad26.COV2.S (Janssen); Other: CoronaVac (Sinovac)

Interventions

ChAdOx1 nCOV-19 vaccine (Vaxzeria) OTHER

Used as 2nd booster, 1st booster, or primary series

Population A; Population B

BNT162b2 (Pfizer) OTHER

Used as 2nd booster, 1st booster, or primary series.

Population A; Population B

Ad26.COV2.S (Janssen) OTHER

Used as 2nd booster, 1st booster, or primary series.

Population A; Population B

CoronaVac (Sinovac) OTHER

Used as 2nd booster, 1st booster, or primary series.

Population A; Population B

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Population A is for evaluating second booster doses and will consist of individuals aged 18 years and over with immunocompromising conditions, healthcare workers aged 18 years and over, and individuals aged 50 years and over. Population B is for evaluating first booster doses and will consist of all individuals aged 18 and over.

You may qualify if:

• Hospitalized for SARS between 01 January 2022 and 31 December 2022 (Population A) or hospitalised for SARS between 01 August 2021 and 31 December 2022 (Population B).
• Eligible for a second COVID-19 vaccine booster dose at the time of SARS hospitalization (i.e., aged 50+ or aged 18+ and either a HCW or with an IC) for second booster objectives \[Population A\] OR eligible for a first COVID-19 vaccine booster dose at the time of SARS hospitalisation (i.e., aged 18+) for first booster objectives \[Population B\].
• Results available for a RT-PCR and/or antigen test for SARS-CoV-2 conducted on a sample taken up to 14 days after symptom onset.
• Individuals have required matching variables (e.g. age and sex).

You may not qualify if:

• Hospitalized for COVID-19 within 3 months prior to date of current hospital admission for SARS
• Nosocomially-acquired infection (where SARS case is flagged as nosocomial and/or where symptom onset date is after hospitalisation date)

Sponsors & Collaborators

• AstraZeneca: lead

Study Sites (1)

Techtrials Pesquisa e Tecnologia Ltda.

São Paulo, 05403-010, Brazil

Location

Related Publications (1)

• Meeraus W, Postema A, Gray CM, Lee A, Maria AS, Furtado BE, Conde-Sousa E, Ouwens M, Valverde DA, da Cunha CA, Barbosa AN, Corte C, Taylor S. Second booster doses of adenoviral- and mRNA-based COVID-19 vaccines increase protection against COVID-19 hospitalization: Final analysis from the REFORCO-Brazil real-world effectiveness study during Omicron. Vaccine. 2025 Apr 19;53:126955. doi: 10.1016/j.vaccine.2025.126955. Epub 2025 Mar 10.

  PMID: 40068393 DERIVED

Related Links

• Redacted CSR Synopsis

MeSH Terms

Conditions

COVID-19

Interventions

ChAdOx1 nCoV-19; BNT162 Vaccine; Ad26COVS1; sinovac COVID-19 vaccine

Condition Hierarchy (Ancestors)

Pneumonia, Viral; Pneumonia; Respiratory Tract Infections; Infections; Virus Diseases; Coronavirus Infections; Coronaviridae Infections; Nidovirales Infections; RNA Virus Infections; Lung Diseases; Respiratory Tract Diseases

Intervention Hierarchy (Ancestors)

Vaccines, DNA; Nucleic Acid-Based Vaccines; Vaccines, Synthetic; Vaccines; Biological Products; Complex Mixtures; COVID-19 Vaccines; Viral Vaccines; mRNA Vaccines; Recombinant Proteins; Proteins; Amino Acids, Peptides, and Proteins; Antigens; Biological Factors

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: RETROSPECTIVE
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 23, 2023
• First Posted: January 26, 2023
• Study Start: July 22, 2022
• Primary Completion: May 18, 2023
• Study Completion: May 18, 2023
• Last Updated: November 21, 2024

Record last verified: 2024-11

Locations

BR (1)