EFFICACY OF 2 DOSES OF RIT 4237 BOVINE ROTAVIRUS VACCINE FOR PREVENTION OF ROTAVIRUS DIARRHEA

Candidate oral bovine rotavirus vaccine RIT 4237 or placebo was given to 252 Finnish infants at birth and at 7 months of age. No vaccine-associated reactions were observed. Primary rotavirus ELISA IgM responses were detected in 36% of the infants after the first vaccination; after the second dose 68% of the vaccinees were seropositive for rotavirus ELISA IgG antibody. The infants remained in clinical follow-up over two rotavirus epidemic seasons (total 28 months). Counted from child years in follow-up the overall vaccine protection rate was 43%. The clinical severity of rotavirus episodes was assessed using a numerical score 0-20. Vaccine protection rate for cases with a score greater-than-or-equal-to 7 was 57% and for cases with a score greater-than-or-equal-to 11 it was 89%. It is concluded that vaccination with a bovine rotavirus vaccine at birth and at 7 months of age, with the second dose given shortly before rotavirus epidemic season, protects infants against moderately severe and severe rotavirus diarrhoea in the first 2 years of life.