A Phase 1 Study to Evaluate Safety and Reactogenicity of a Vietnamese Rotavirus Vaccine (Rotavin-M1 at 10e6.3FFU/Dose) Among Healthy Adults in Vietnam

Rotavirus (RV) is the most important cause of acute gastroenteritis in children worldwide. In Vietnam rotavirus causes an estimated 122,000-140,000 hospitalizations and 2900-5400 deaths per year among children under 5 years of age (1). Over the past 13 years, sentinel hospital surveillance identified rotavirus in 44%-62% of children admitted for the treatment of acute diarrhea in Vietnam (2-4). Such a high burden of disease justified accelerated development of a new and locally manufactured vaccine against rotavirus in Vietnam. It is estimated that if a vaccine was introduced in the current childhood immunization schedule, it could reduce severe rotavirus disease by about 60% or more given current vaccine efficacies and coverage (5).

The Government of Vietnam has pursued a policy to encourage local vaccine production so the country could be self-reliant with affordable vaccines for its population (6). Over the past decades, several locally produced vaccines for poliomyelitis, cholera, Japanese encephalitis, and Diphtheria-Pertussis-Tetanus have contributed to the reduction in the prevalence of these diseases and to the eradication of polio over the past decade. While two commercial rotavirus vaccines, RotarixTM (GSK, Belgium) and RotaTeq® (Merck), have both been tested in Vietnam, neither is currently available at an affordable cost for the national program. Therefore, the candidate vaccine, Rotavin-M1, was developed in order to fill this need for a more affordable vaccine for Vietnamese children (6). This vaccine is similar to RotarixTM, and was developed by selecting a common G1P[8] strain and attenuating it through serial