A Bovine Parainfluenza Virus Type 3 Vaccine Is Safe and Immunogenic in Early Infancy

BackgroundA phase 2 trial was conducted to assess in young infants the safety, tolerability, infectivity, and immunogenicity of multiple doses of an intranasal vaccine using bovine parainfluenza virus type 3 (bPIV3) MethodsOne hundred ninety-two healthy 2-month-old infants were randomized 1:1:1 to receive 1×105 median tissue culture infective dose (TCID50) bPIV3 vaccine, 1×106 TCID50 bPIV3 vaccine, or placebo at 2, 4, 6, and 12–15 months of age. Safety information was collected by use of diary sheets and telephone interviews. Nasal wash and serum specimens were collected for assessment of infectivity and immunogenicity ResultsThe safety profiles of both dosages of bPIV3 were similar to that of placebo, with the exception of fever with temperature of ⩾38.1°C after dose 2 only, occurring in 34% of the 1×105 TCID50 group, 35% of the 1×106 TCID50 group, and 12% of the placebo group (P