Treatment of respiratory syncytial virus infection with recombinant interferon alfa-2a.

A prospective randomised, double blind, controlled trial was conducted in 52 infants to determine whether recombinant interferon alfa-2a (INF-alpha-2a) would reduce the morbidity of acute bronchiolitis and the respiratory syncytial virus shedding time. All infants had a positive direct antigen immunofluorescence test for respiratory syncytial virus. INF-alpha-2a (50,000 IU/kg/day) or placebo was administered by daily intramuscular injection for three consecutive days. Sixteen infants received INF-alpha-2a and 36 received placebo treatment. The two groups were similar in demographic characteristics and initial oxygenation. The treatment group, however, had a significantly higher overall score for severity of illness at the start of treatment. More rapid drop of the clinical score was observed in the INF-alpha-2a group after treatment in the first three days and the two groups had similar clinical severity by day 3. There was no significant difference of the duration of viral shedding in the two groups. In conclusion, the overall clinical improvement was greater in the treatment group over the first three days, but the duration of viral shedding was not altered.