Figure 2. . Phylogenetic analysis of vaccinia virus (VACV) isolates. A) Phylogenetic tree based on the nucleotide sequence of the orthopoxvirus hemagglutinin gene. VACV Serro bovine (SB1V), VACV Serro human 1 and 2 (SH1V and SH2V) grouped with VACV group 2 isolates, far from other VACV group 1 members. These isolates grouped far from (outliers) Serro-2 virus, a VACV isolated in the same geographic region. B) Phylogenetic tree based on the nucleotide sequence of the orthopoxvirus ati gene. The hemagglutinin tree shows SH2V grouping with VACV Western Reserve (WR) and SPAn232 virus, members of VACV group 2, not close to other isolates from Brazil. The neighbor-joining method with the Tamura-Nei model of nucleotide substitutions in the MEGA4 software program (www.megasoftware.net/) was used. Bootstrap confidence intervals are shown on branches (1,000 replicates) with GenBank accession numbers. MPXV, monkeypox virus; CPXV, cowpox virus; HSPV, horsepox virus; VARV, variola virus. Black dots indicate samples isolated during the 2011 outbreak of bovine vaccinia in Brazil. Scale bars indicate nucleotide substitutions per site.