LAUSR

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.