A live, attenuated respiratory syncytial virus and parainfluenza virus type 3 vaccine was evaluated in healthy respiratory syncytial virus/parainfluenza virus type 3 seropositive children aged 1 to 9 years. Three cohorts of 40 children were randomized 1:1 to receive 104, 105 or 106 median tissue culture infectious dose50 MEDI-534 vaccine of placebo. The vaccine's safety profile was similar to placebo, no viral shedding was detected, and the vaccine was minimally immunogenic.
Gomez M, Mufson MA, Dubovsky F, Knightly C, Zeng W, Losonsky G. “Phase I study of MEDI-534, of a live, attenuated intranasal vaccine against respiratory syncytial virus and parainfluenza-3 virus in seropositive children,” The Pediatric Infectious Disease Journal. 2009 July 28(7):655-8.