Live-Attenuated Respiratory Syncytial Virus Vaccines

Live-attenuated respiratory syncytial virus (RSV) vaccines offer several advantages for immunization of infants and young children: (1) they do not cause vaccine-associated enhanced RSV disease; (2) they broadly stimulate innate, humoral, and cellular immunity, both systemically and locally in the respiratory tract; (3) they are delivered intranasally; and (4) they replicate in the upper respiratory tract of young infants despite the presence of passively acquired maternally derived RSV neutralizing antibody. This chapter describes early efforts to develop vaccines through the classic methods of serial cold-passage and chemical mutagenesis, and recent efforts using reverse genetics to derive attenuated derivatives of wild-type (WT) RSV and to develop parainfluenza vaccine vectors that express RSV surface glycoproteins.