Genetic characterization of P[8] rotavirus strains circulated in Iran between 2009 and 2017.

Group A rotavirus (RVA) is the most common cause of acute gastroenteritis worldwide, which is responsible for causing an estimated 120 000 deaths in children under 5 years of age, which mostly occur in the lower-income countries of Asia and Africa. The G1P[8] is a common genotype of RVA that has spread throughout the world, including Iran and this genotype is present in two commonly used RVA vaccines, RotarixTM and RotaTeqTM . In this study, we investigated the genetic diversity, viral evolution, and differences between antigenic epitopes of Iran's P[8] strains and two licensed vaccines. The phylogenetic and evolutionary analysis was carried out, using MEGA version 6.0 and BEAST, respectively. Antigenic epitopes of VP8* were compared to determine the differences between strains from Iran and RotarixTM and RotaTeqTM . The P[8]-lineages III and IV were found as the predominant P genotype that circulated in Iran. The TMRCA of P[8]-lineages III and IV was estimated in 1987 and 2009, respectively. The P[8]-lineage III strains showed 12 amino acid changes compared to RotarixTM and 10 amino acid changes compared to RotaTeqTM . The P[8]-lineage IV strains showed 10 amino acid variations for both RotarixTM and RotaTeqTM strains. The results revealed that the P[8] strains circulating in Iran differ from RotarixTM and RotaTeqTM strains. To monitor the long-term effects of vaccines on the emergence of P[8] strains with different lineages, routine and successful monitoring of these strains will be crucial.