Strain diversity plays no major role in the varying efficacy of rotavirus vaccines: An overview

While a monovalent Rotarix® [RV1] and a pentavalent RotaTeq® [RV5] have been extensively tested and found generally safe and equally efficacious in clinical trials, the question still lingers about the evolving diversity of circulating rotavirus strains over time and their relationship with protective immunity induced by rotavirus vaccines. We reviewed data from clinical trials and observational studies that assessed the efficacy or field effectiveness of rotavirus vaccines against different rotavirus strains worldwide. RV1 provided broad clinical efficacy and field effectiveness against severe diarrhea due to all major circulating strains, including the homotypic G1P[8] and the fully heterotypic G2P[4] strains. Similarly, RV5 provided broad efficacy and effectiveness against RV5 and non-RV5 strains throughout different locations. Rotavirus vaccination provides broad heterotypic protection; however continuing surveillance is needed to track the change of circulating strains and monitor the effectiveness and safety of vaccines.