FIG. 2.

The eight unique PvMSP-1 block 2 sequences found in P. vivax isolates circulating in the study area in 1999 and 2004 to 2005 and their absolute frequencies. The lowercase letter indicates a codon with a synonymous nucleotide replacement. Repetitive motifs are underlined. Four sequences (sequences II, III, VI, and VIII, corresponding to 69.8% of all block 2 sequences) match sequences found in recombinant antigens used in serology (BR07, BP39, BP13, and BP30, respectively). The remaining block 2 antigens, Belém and BP29, are quite similar to sequences III (91.5% amino acid identity) and VI (96.3% amino acid identity), respectively.