A DS-1 like G9P[6] human strain CDC-6 as a new rotavirus vaccine candidate

Human rotavirus vaccine Rotarix® (G1P[8]) has shown broad cross protection against homotypic and heterotypic Wa-like human rotavirus strains among children worldwide. This vaccine, however, appears to induce slightly less or non-consistent protection against DS-1 like rotavirus P[4] strains in some settings. In addition, children who are secretor or Lewis-negative and are vaccinated with Rotarix® often experience breakthrough infection with P[6] strains. By contrast, P[6] strains infect all children, irrespective of their secretor or Lewis status. In the present study, we report successful adaptation of a DS-1 like human rotavirus G9P[6] strain (CDC-6) to high growth in Vero cells and identify sequence changes that may be critical for enhanced growth in vitro and attenuation in vivo. This human G9P[6] strain could serve as a promising new and potential low-cost vaccine candidate for global use, particularly in targeted population with secretor or Lewis-negative status and high prevalent DS-1 like P[6] strains.