Purpose of review: To report on recent progress on the development and implementation of a vaccine against respiratory syncytial virus (RSV), on investigations of the mechanism of action of prophylactic antibodies and the potential for increased efficacy of those antibodies, and on candidate antiviral drugs against RSV.
Recent findings: Follow-up data from RSV live attenuated vaccine trials in naïve infants and young children strengthen the view that live attenuated vaccines will not predispose to exacerbated pneumonia upon natural infection. Data on the age distribution of RSV disease from the developing country setting highlight a need to investigate the effectiveness of live attenuated vaccination outside the 0-2 month age group. It has recently been shown that palivizumab, the only approved monoclonal antibody for prophylaxis of RSV, and which is used mainly in infants at high risk of severe RSV disease, allows abortive replication of the virus in the lungs of cotton rats. It has also been reported that a variant of palivizumab, motavizumab, has greater affinity for RSV and is now being investigated in clinical trials. Progress has been made on the development of antiviral compounds including RSV604, a novel benzodiazepine, and ALN-RSV01, based on a small interfering RNA.
Summary: Advances in the treatment of RSV are more evident than in prevention. Obstacles to prevention of paediatric RSV disease may require new approaches to vaccine delivery.