Inactivated rotavirus vaccines: a priority for accelerated vaccine development.

Live oral rotavirus vaccines have proven to be generally safe and effective to prevent severe dehydrating diarrhea among children in high and some middle income countries. However, concerns linger about rare but severe adverse events, such as intussusception and their efficacy against the full range of rotavirus serotypes. More importantly, live oral vaccines have been less immunogenic and results of trials to assess their efficacy in poor children of both Africa and Asia will not be available for 2-3 years. This review describes the rationale for developing an inactivated rotavirus vaccine (IRV) as an alternative approach should live oral vaccines not work well in these challenging populations. Studies have demonstrated the protective role of serum antibody in animals and children and the robust serum antibody response and protection against rotavirus infection in animal models following parenteral immunization with IRV. Four years after licensing the first new generation of rotavirus vaccine, we still remain several years away from knowing how well they work in the target populations. Research to develop alternative approaches should be fostered as an insurance policy to protect against suboptimal efficacy or unanticipated adverse events that could hinder global immunization and protection of all children.