Rotavirus group A (RVA) is the most important cause of diarrhea, accounting for about 40% of morbidity and mortality related to this disease in children around the world before the introduction of the vaccine. After the introduction of the vaccine against the RVA in Brazil in 2006 genotype G2RVA he rose again, being detected in up to 82% of children under five years of age performed post vaccination studies, leading to questions about the protection afforded by the vaccine facing the G2 type, as well as the occurrence of a selective pressure vaccine. Little is known about the evolution and diversity of G2 genotype and the possible influence of the vaccine on this. To provide a better understanding of the flow and genetic diversity of RVA genotype G2, we perform the time of circulation analysis of genotype over 31 years and analysis of structural and non-structural genes from samples that have circulated over 20 years in northern region of Brazil. The temporal assessment of movement of different genotype circulating in this region has observed that the G2 type RVA presented over the years a cyclical pattern of occurrence that did emerge in a post deployment of the vaccine scenario, suggesting a natural fluctuation due to variations natural occurring over time. Phylogenetic analyzes showed that for VP7 lines G2 there is a continuous, responsible for a movement of rotation in the lines being detected two lines and three sublineages over 20 years. Three important substitutions in antigenic regions of VP7 (A87T, D96N and S213D) were identified in samples that circulated from the 90. These changes may have increased the capacity of the circulating strains in environments where there is vaccine coverage for RVA. All G2P[4] strains analyzed revealed a DS-1-like genome constellation: I2-R2-C2-M2-A2-N2-T2-E2-H2. However, several viral variants circulated during the study period. No differences were observed in the antigenic sites of the VP8 * and VP7 proteins between samples that circulated in the period before and after the introduction of the vaccine. For VP2 and VP3 genes was evident in some samples a strong correlation with animal genes. This study provides evidence of genetic diversity in G2 genotype RVA, suggesting that this type has natural characteristics fluctuation and its emergence after the implementation period of the vaccine is more directly associated with ecological characteristics of the virus than a vaccine pressure.
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