BACKGROUND: Antigens expressed in sexual stages of the malaria parasites are targets of transmission blocking vaccines TBVs . ...Wright's fixation index showed low to moderate genetic differentiation of P. vivax populations in the GMS, with F ST ranging from 0.04077 to 0.24833, whereas high levels of genetic differentiation were detected between the China Myanmar border and Iran populations F ST 0.60266 , and between Thailand and Iran populations F ST 0.44161 . ...