The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemic in Brazil was dominated by two lineages designated as B.1.1.28 and B.1.1.33. The two SARS-CoV-2 variants harboring mutations at the receptor-binding domain of the Spike (S) protein, designated as lineages P.1 and P.2, evolved from lineage B.1.1.28 and are rapidly spreading in Brazil. Lineage P.1 is considered a Variant of Concern (VOC) because of the presence of multiple mutations in the S protein (including K417T, E484K, N501Y), while lineage P.2 only harbors mutation S:E484K and is considered a Variant of Interest (VOI). On the other hand, epidemiologically relevant B.1.1.33 deriving lineages have not been described so far. Here we report the identification of a new SARS-CoV-2 VOI within lineage B.1.1.33 that also harbors mutation S:E484K and was detected in Brazil between November 2020 and February 2021. This VOI displayed four non-synonymous lineage-defining mutations (NSP3:A1711V, NSP6:F36L, S:E484K, and NS7b:E33A) and was designated as lineage N.9. The VOI N.9 probably emerged in August 2020 and has spread across different Brazilian states from the Southeast, South, North, and Northeast regions.

The SARS-CoV-2 variant assigned to PangoLineage C.37 was first reported in late December 2020 in Peru and by April 2021 was responsible for 97% of new infections in that country. ¹ It is currently expanding in Chile and Argentina, and there is evidence of onward transmission in Colombia, Ecuador, Mexico, the USA, Germany and Israel. ² C.37 presents 30 molecular signatures, seven nonsynonymous substitutions (G75V, T76I, R246N, L452Q, F490S, D614G, T859N) and a deleted region (Δ247–253) in the Spike protein. ¹ Another deleted region is found in the ORF1a gene (Δ3675–3677) also present in variants of concern Alpha, Beta and Gamma. ¹ Due to genomic characteristics and epidemiological relevance, on 15 June 2021, WHO designated C.37 as Variant of Interest (VOI) Lambda. ^{2,. 3}