IMPAACT 2000

IMPAACT 2000 is a double-blind, randomized, placebo-controlled trial that will evaluate the safety and immunogenicity of Recombinant Live-Attenuated Respiratory Syncytial Virus Vaccine RSV LID ΔM2-2 in infants and children confirmed to be RSV-seronegative within 42 days prior to inoculation.  Approximately 51 healthy RSV-seronegative infants and children ≥6 months (180 days) to <25 months (750 days) of age will be enrolled to yield 45 subjects with evaluable results.  Eligible infants and children will receive a single dose of RSV LID ΔM2-2 vaccine or placebo intranasally at entry.  Children will be enrolled in the protocol between April 1st and October 14th (outside of RSV season) and will remain on study until they complete the post-RSV season visit between April 1st and April 30th in the calendar year following enrollment.