Respiratory syncytial virus (RSV) is the leading cause of infant pneumonia and bronchiolitis in infants and children. In the absence of a proven effective therapy, high risk infants have been targeted for prevention. Historical data and animal studies suggested that passive immunization with antibody enriched with RSV neutralizing activity might be an effective method for prevention. Respigam™, an intravenous immune globulin with six to ten fold the neutralizing antibody in commercially available human intravenous immune globulin, was developed. A previous clinical trial of Respigam™ prophylaxis in high risk infants (i.e. prematurity, bronchopulmonary dysplasia, congential heart disease) suggested that monthly administration of 750 mg/kg may be associated with a reduction in severity of RSV illness and a reduction in the rate of RSV hospitalization. A recently completed randomized double-blind placebo controlled clinical trial at 54 centers with 510 high risk infants (i.e. prematurity, bronchopulmonary dysplasia) confirmed the effectiveness of this intervention in reducing the incidence and total days of both RSV hospitalization and overall respiratory hospitalization. As a result, Respigam™ was approved by the Food and Drug Administration for this indication. Although this intervention appears to cost about $5,000 per patient for a full respiratory season, it appears to be cost effective based upon the cost per year of lives saved. Even though Respigam™ appears safe, (i.e. < 3% of children who received this treatment have reported medically significant adverse events) continued follow-up of treated infants would be prudent. While some have suggested additional factors which might limit or expand the groups of patients treated, further clinical and pharmacoeconomic studies are needed to answer these assumptions.