Figure 2. Phylogenetic tree based on nucleotide sequences of the complete hemagglutinin open reading frame (921 bp) from the llama orthopoxvirus isolate (arrow) and additional orthopoxvirus sequences available in GenBank. The tree has been constructed by using nucleotide alignment, the Kimura 2-parameter algorithm, and the neighbor-joining method implemented in MEGA4.1 software (www.megasoftware.net). Bootstrap values >75 are shown at nodes. CPXV, cowpox virus; CMLV, camelpox virus; VARV, variola virus; ECTV, ectromelia virus; VACV, vaccinia virus; MPXV, monkeypox virus. Scale bar indicates genetic diversity at the nucleotide level.