Effectiveness of CoronaVac, ChAdOx1 nCoV-19, BNT162b2, and Ad26.COV2.S among Individuals with Previous SARS-CoV-2 Infection in Brazil: A Test-Negative, Case-Control Study

Using national COVID-19 notification, hospitalization, and vaccination datasets from Brazil, researchers did a test-negative, case-control study to assess the effectiveness of four vaccines for individuals with laboratory-confirmed previous SARS-CoV-2 infection.