Phylogenetic and immunoinformatic analysis of VP4, VP7, and NSP4 genes of rotavirus strains circulating in children with acute gastroenteritis in Indonesia

Rotavirus is a major cause of diarrhea in Indonesian children. However, rotavirus vaccines have not been introduced in the national immunization program of Indonesia. Understanding the genetic diversity and conserved antigenic regions of circulating strains are therefore essential to assess the potential efficacy of rotavirus vaccines. We collected fecal samples from hospitalized children less than 5 years of age with acute diarrhea. Rotavirus genotyping was performed by reverse transcriptase polymerase chain reaction, followed by sequencing of the VP4, VP7, and NSP4 genes of representative strains. Phylogenetic analysis was performed to investigate their relationship with globally circulating strains. Conservational analysis, immunoinformatics, and epitope mapping in comparison to vaccine strains were also performed. The sequence analyses showed that differences of multiple amino acid residues existed between the VP4, VP7, and NSP4 antigenic regions of the vaccine strains and the Indonesian isolates. However, many predicted conserved epitopes with higher antigenicity were observed in the vaccine and Indonesian strains, conferring the importance of these epitopes. The identified epitopes showed a higher potential of rotavirus vaccine to be employed in Indonesia. It could also be helpful to inform the design of a peptide vaccine based on the conserved regions and epitopes in the viral proteins.