High transmission of SARS-CoV-2 in Amazonia, Brazil: an epidemiological strategy to contain severe cases of COVID-19

• Published in: Journal of public health policy 2024-12
• Main Authors: Ferrante, Lucas, Capanema, Eduardo, Steinmetz, Wilhelm Alexander Cardoso, Nelson, Bruce Walker, Almeida, Alexandre Celestino Leite, Leão, Jeremias, Pereira, Letícia Sarturi, Vassão, Ruth Camargo, Fearnside, Philip Martin, Tupinambás, Unaí
• Format: Article
• Language: English
• ISSN: 0197-5897; 1745-655X; 1745-655X
• DOI: 10.1057/s41271-024-00530-0

We followed the COVID-19 pandemic in Manaus, one of the epicenters of COVID-19 in Brazil, using an epidemiological mathematical model and made five main conclusions. First, in early 2022, the actual cases exceed officially reported data by up to 8 times. Second, despite vaccination campaigns, the collective immunity threshold necessary was insufficient to contain severe cases of COVID-19. Next, the low observed mortality demonstrated the effectiveness of vaccination. Next, the drop in the vaccination rate combined with immune escape by the Omicron sub-variants (BA.2.12.1, BA.4, and BA.5) resulted in new wave after November 2022. Finally, to minimize severe cases of COVID-19, we need to raise vaccination thresholds above 90-95% of the entire population including children aged 6 months and older and require booster doses at least in four-month intervals. This approach would help to prevent severe cases of COVID-19 that cause hospitalizations and deaths.