Study registration: *
Publication Ranzani O, medRxiv, 2021
Dates: 2021-01-17 to 2021-04-29
Funding: Public/non profit (Pan American Health Organization; Sao Paulo State; Oswaldo Cruz Foundation; Instituto de Salud Carlos III; Spanish Ministry of Science and Innovation through the Centro de Excelencia Severo Ochoa; Generalitat de Catalunya through the CERCA Program.)
Conflict of interest: no COI (The authors have declared no competing interest; no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.)

Methods

Study design:Test-negative
Description of participants: Adults ≥70 years of age, residents of São Paulo State and who underwent SARS-CoV-2 RT-PCR testing in multiple centers in Brazil
Inclusion criteria:
  • Adults ≥70 years of age who had a residential address in São Paulo State
  • underwent SARS-CoV-2 RT-PCR testing during the study period
  • and had complete and consistent information between data sources on age, sex, residence, and vaccination and testing status and dates.

Exclusion criteria:
  • Have received ChAdOx1 vaccine before sample collection for RT-PCR testing
  • positive RT-PCR test in the preceding 90-day period

Follow-up duration (months): 3.4
Vaccines:
  • 1 or 2 doses of Coronavac
Variant description :
Variant name: Gamma
Evidence: Indirect evidence (prevalence of variant in the population: 86%)
Documents
available

Protocol

Yes. In English

Statistical plan

Yes

Data-sharing stated: Yes
Data accessibility: Deidentified databases as well as the R codes will be deposited in the repository, https://github.com/juliocroda/VebraCOVID-19
General comment Main concern was over possible selection bias due to the fact that those with non-missing race were excluded (and this could possibly be influenced by both vaccination status and case/control status); for hospitalisation and mortality a planned sensitivity analysis to address potential selection bias was not presented. Also some concerns over residual confounding for hospitalisation and mortality.