Fig. 1

Phylogenetic analysis of VACV-BR based on nucleotide sequences of the A56R gene (hemagglutinin). VACV-BR group 1 is highlighted with light yellow and group 2 with light blue. White arrows indicate the Brazilian viruses used in this study. The alignment was built using Muscle with standard parameters [45]. The maximum likelihood tree was built with IQ-TREE [46]. The best-fit replacement model selected by ModelFinder was HKY + F + I. The branch supports were estimated using 1000 replicates of standard bootstrap and the tree was visualized with iTOL [47]. Bootstrap values lower than 50 were suppressed. The clade of variola viruses has been collapsed. The scale bar indicates the number of substitutions per site. A schematic alignment was included (inset) to indicate the genomic signature that divides VACV-BR into two distinct groups, an 18-nt deletion between positions 740 and 757 of the A56R gene. The representation was based on the VACV-WR (AY243312) gene