B-cell epitope predictions were carried out on 24 amino acids of PvMSP1 Block 2 using the BepiPred 1.0 Server .
Still, the sequence PvMSP1 Block 2 of haplotype number 7 was similar to that of strain Sal-1.
However the alignment of several PvMSP1 alleles of the Block 2 possessed an apparent tandem degenerating 5-mer repeat (GSXXX) that could range from 0 to 9 repetitions .
Regarding the PvMSP1 Block 2 sequences found in Manaus, two of them were similar to major Belem and Sal-1 haplotypes, number 1 and number 7, respectively.
According to Valderrama-Aguirre , acquisition of natural IgG antibodies against a panel of allelic variant proteins of major polymorphic blocks of PvMSP1 showed that the Block 2 was poorly immunogenic although it had been the most recognized by subjects exposed to malaria in western Brazilian Amazon indicating that the acquisition of variant-specific response requires successive boosting of these polymorphic blocks .
vivax patients had been previously, identified high levels of antibodies against the N-terminus of PvMSP1 were observed in individuals clinically protected from malaria.
Assessing the acquired immune response against N-terminus PvMSP1, levels of IgG3 anti-ICB2-5 were higher in symptomless in Plasmodium vivax infected individuals than those of subjects who had acute malaria or those uninfected ones, raising importance of the N-terminus PvMSP1 to the rationale of malaria vaccine designs .