Impact of SARS-CoV-2 Gamma lineage introduction and COVID-19 vaccination on the epidemiological landscape of a Brazilian city
Cecília Ártico Banho, Lívia Sacchetto, Guilherme Rodrigues Fernandes Campos, Cíntia Bittar, Fábio Sossai Possebon, Leila Sabrina Ullmann, Beatriz de Carvalho Marques, Gislaine Ceslestino Dutra da Silva, Marília Mazzi Moraes, Maisa Carla Pereira Parra, Andréia Francesli Negri, Ana Carolina Boldrin, Michela Dias Barcelos, Talita Mirelle Dourado Santos, Bruno Henrique Gonçalves de Aguiar Milhim, Leonardo Cecílio da Rocha, Fernanda Simões Dourado, Andresa Lopes dos Santos, Victoria Bernardi Ciconi, Caio Patuto, Alice F. Versiani, Rafael Alves da Silva, Edoardo Estevam de Oliveira Lobl, Victor Miranda Hernandes, Nathália Zini, Carolina Colombelli Pacca, Cássia Fernanda Estofolete, Helena Lage Ferreira, Paula Rahal, João Pessoa Araújo, Jamie A. Cohen, Cliff C. Kerr, Benjamin M. Althouse, Nikos Vasilakis, Maurício Lacerda Nogueira
Abstract
Background: The emergence of the Brazilian variant of concern, Gamma lineage (P.1), impacted the epidemiological profile of COVID-19 cases due to its higher transmissibility rate and immune evasion ability. Methods: We sequenced 305 SARS-CoV-2 whole-genomes and performed phylogenetic analyses to identify introduction events and the circulating lineages. Additionally, we use epidemiological data of COVID-19 cases, severe cases, and deaths to measure the impact of vaccination coverage and mortality risk. Results: Here we show that Gamma introduction in São José do Rio Preto, São Paulo, Brazil, was followed by the displacement of seven circulating SARS-CoV-2 variants and a rapid increase in prevalence two months after its first detection in January 2021. Moreover, Gamma variant is associated with increased mortality risk and severity of COVID-19 cases in younger age groups, which corresponds to the unvaccinated population at the time. Conclusions: Our findings highlight the beneficial effects of vaccination indicated by a pronounced reduction of severe cases and deaths in immunized individuals, reinforcing the need for rapid and massive vaccination.