Rhesus Rotavirus Candidate Vaccine

Abstract

• Live attenuated oral rhesusRotaviruscandidate vaccine (strain MMU 18006 [lot RRV-1]) was evaluated for immunogenicity, safety, and clinical protection in a double-blind, placebo-controlled trial involving 200 infants aged 2 to 5 months when vaccinated. Vaccine-induced fourfold or greater rise ofRotavirusantibodies was seen in 62% of the infants. Febrile reactions of short duration on days 3 and/or 4 after vaccination occurred in 26% of the vaccine recipients. The clinical follow-up covered twoRotavirusseasons, in which serotypes 1 and 4 were prevalent. There were 16 cases of confirmedRotavirusdiarrhea in the placebo-treated group and 10 in the vaccine-treated group; from this a vaccine protection rate of 38% was derived. Clinical severity ofRotavirusdiarrhea was assessed by a score; 13 cases in the placebo-treated group and 5 in the vaccine-treated group were regarded as severe or moderately severe, giving a vaccine protection rate of 67%. The rhesusRotavirusvaccine induces partial protection against heterotypicRotavirusdisease, but the level of protection achieved with the present vaccine dose in this age group appears to be insufficient for a generalRotavirusvaccination. (AJDC.1990;144:285-289)