Evaluation of two chimeric bovine-human parainfluenza virus type 3 vaccines in infants and young children

► rB/HPIV3 & rHPIV3-NB contain ≥1 internal gene from BPIV3 & HN & F genes from HPIV3. ► In phase I trials both vaccines induced antibody in HPIV3-naïve children. ► rB/HPIV3 was significantly more restricted in replication than rHPIV3-NB. ► rB/HPIV3 induced significantly higher HPIV3 antibody titers than rHPIV3-NB. ► rB/HPIV3 is the preferred candidate for further clinical development.