REVIEW OF G-TYPING AND P-TYPING RESULTS FROM A GLOBAL COLLECTION OF ROTAVIRUS STRAINS - IMPLICATIONS FOR VACCINE DEVELOPMENT

Candidate rotavirus vaccines have been prepared with reassortant strai ns specifically to protect against the 4 major rotavirus G serotypes ( G1-4). Many studies using P (VP4) genotyping methods have indicated th at, worldwide, rotavirus strains of the 4 common G serotypes are each associated with 1 P genotype: G1, G3, and G4 are associated with P[8], and G2 is associated with P[4]. In contrast, G and P genotyping of ro tavirus in specimens from India revealed that a high percentage of the childhood diarrhea strains belong to genotype P[6], and the most comm on strain had an unusual G serotype, G9. Similarly, in all regions sur veyed in Brazil, apparent reassortants of genotype P[8], G5 were found in children with gastroenteritis. These studies indicate that while r otavirus strains have limited diversity in many settings, reassortment between common and uncommon serotypes or animal strains can arise in some settings and, thus, lead to unusual diversity.