In order to address the reduced efficacy and effectiveness of oral RV vaccinations in low-income countries, non-replicating parenteral rotavirus (RV) vaccine candidates are being developed. One of the leading possibilities is a shortened recombinant VP8* protein produced in Escherichia coli from original sequences of prototype RV genotypes P[8], P[4], or P[6] identified prior to 1983. Given the considerable variability of VP8*It was thought worthwhile to investigate the evolutionary changes of RV strains reported worldwide throughout time in connection to the three P2-VP8 vaccine strains. Researchers obtained 6,366 RV VP8* gene sequences from GenBank of P[8], P[4], or P[6] strains isolated between 1974 and 2017, across 77 countries, and compared them to the three P2-VP8 vaccine strains: Wa, DS-1, and 1076. Phylogenetic research revealed that non-vaccine lineages account for 94.9 percent, 99.8 percent, and 100 percent of the P[8], P[4,] and P[6] strains reported globally between 1974 and 2018. These P[8], P[4], and P[6] RV strains vary from the corresponding vaccination strains by a mean of 9%, 5%, and 6%, respectively.

In the U.S, the mean percentage difference between all P[8] RV strains and the original Wa strain grew over time. The findings support the high evolutionary changes in VP8* of the P[8, P4, and P6] main RV strains, as well as their growing divergence from the candidate subunit vaccine strains over time. These discoveries might lead to the development of novel RV vaccines.