Respiratory syncytial virus immunoglobulin and monoclonal antibodies in the prevention and treatment of respiratory syncytial virus infection.

Respiratory syncytial virus (RSV) infection is particularly severe in infants with bronchopulmonary dysplasia (BPD) and in premature infants without BPD. Attempts to develop a vaccine against RSV have been unsuccessful. Passive immunoprophylaxis of premature infants with or without BPD using a hyperimmune human globulin against RSV (RSVIg) decreases the severity of RSV infection such that the rate of hospitalization following infection is reduced by 40%. The severity of illness among hospitalized infants is also reduced. To avoid the difficulties associated with intravenous infusion of immunoglobulins, monoclonal IgG antibodies against the fusion protein of RSV have been developed. In one trial, the antibodies were ineffective, although subsequent trials using higher doses of the antibody show more promising results. Studies of IgA monoclonal antibodies directed against RSV, which are administered in the form of nose drops, are also in progress. None of these preparations appear to be effective in the treatment of established RSV infection. Each of the preparations appeared to be safe, with one exception. Infants with cyanotic heart disease who received RSVIg had an increased risk of surgical complications, perhaps related to increases in serum viscosity as a result of receiving the hyperimmunoglobulin monthly in doses of 750 mg/kg. While definitive cost/benefit analyses are pending, RSVIg may be useful in infants and children with BPD who have current or recent oxygen requirements, as well as in certain premature infants without BPD. Recommendations on the use of RSVIg are provided.