Effect of vaccination on COVID-19 hospitalizations and mortality.

1. Hospital de Clínicas de Porto Alegre, Porto Alegre (RS) Brasil. 2. Programa de Pós-Graduação em Ciências Pneumológicas, Universidade Federal do Rio Grande do Sul – UFRGS – Porto Alegre (RS) Brasil. 3. Faculdade de Medicina, Universidade do Vale do Rio dos Sinos – Unisinos – São Leopoldo (RS) Brasil. 4. Faculdade de Medicina, Universidade Federal do Rio Grande do Sul –UFRGS – Porto Alegre (RS) Brasil. COVID-19, caused by SARS-CoV-2, has spread worldwide since December of 2019, causing significant morbidity and mortality. As of July 26, 2023, a total of 768,560,727 cases of COVID-19 had been confirmed worldwide, including 6,952,522 deaths. In Brazil, from January 3, 2020 to July 26, 2023, there were 37,704,598 confirmed COVID-19 cases and 704,488 COVID-19 deaths reported to the WHO.(1)