Safety, infectivity, transmissibility and immunogenicity of rhesus rotavirus vaccine (MMU 18006) in infants

In an attempt to evaluate the immunogenicity, infectivity, transmissibility and safety of rhesus rotavirus vaccine (RRV) MMU 18006, 27 infants ages 5 to 20 months participated in two randomized, double-blind placebo controlled trials, one in a day care setting to allow for child to child contact and close surveillance and the other on an outpatient basis. Fourteen infants (mean age, 8.3 months) received 10(5) plaque-forming units of RRV and 13 (mean age, 11.1 months) received placebo. In the eight infants who participated in the vaccine trial in the day care setting, there was no evidence of transmissibility of RRV, by either stool excretion or seroconversion. The data from both trials showed RRV to be 100% infective and immunogenic in the vaccinees. There were no gastrointestinal side effects although there was an association between vaccine administration and fever occurring on Days 3 and 4. Based on these encouraging preliminary results, further work is proceeding to evaluate this vaccine at lower doses in this age group of infants.