SARS-CoV-2 epidemic in Brazil: how the displacement of variants has driven distinct epidemic waves

Brazi l ranks as third in terms of total number of reported SARS-CoV-2 cases globally. The COVID-19 epidemic in Brazi l was characterised by the co-circulation of multiple variants as a consequence of multiple independent introduction events occurring through time. Here, we describe the SARS-CoV-2 variants that ar e currently circulating and co-circulating in the country, with the aim to highlight which variants have driven the different epidemic waves. For this purpose, we retrieved metadata information of Coronavirus sequences collected in Brazi l and available at the GISAID database. SARS-CoV-2 lineages have been identified along with eleven var-iants, labelled as VOCs (Alpha, Gamma, Beta, Delta and Omicron) VOIs (Lambda and Mu) VUMs (B.1.1.318) and FMVs (Zeta, Eta and B.1.1.519). Here we show that, in the Brazilian context, after 24 months of sustained transmission and evolution of SARS-CoV-2, local variants (among them the B.1.1.28 and B.1.1.33) were dis-placed by recently introduced VOCs firstly with the Gamma, followed by Delta and more recently Omicron. The rapid spread of some of those VOCs (such as Gamma and Omicron) was also mirror by a large increase in the number of cases and deaths in the country. This in t u r n reinforces that, due to the emergence of variants that appear to induce a substantial evasion against neutralizing antibody response, it is important to strengthen genomic ef f o r t within the countr y and how vaccination sti l l remains a critical process to protect the vulnerable population, still at risk of infection and death.