Virus vs. virus: adenovirus vectored vaccine to defeat respiratory syncytial virus

RSV is the single most important vaccine-preventable pediatric disease without a vaccine program. Fears of recurrence of the clinical experience with a formalin-inactivated RSV (FI-RSV) vaccine candidate in the 1960s, which led to enhanced respiratory disease (ERD) and death following natural infection (1), continue to cast a shadow on the development of RSV vaccines for use in infants.