(1)
RSV infection, the main cause of
bronchiolitis, can necessitate hospitalisation, especially of infants at risk, i.e. those with a history of prematurity or bronchodysplasia. No
drug prevention has been available. (2)
Palivizumab, a
monoclonal antibody directed against respiratory syncytial virus (RSV), is now marketed for preventing
respiratory tract infection by RSV in certain infants. (3) The evaluation dossier barely answers the questions raised by the use of this
drug. (4) The results of six trials suggest that the optimal dose is 15 mg/kg
palivizumab by monthly injection throughout the seasonal epidemic period. (5) A double-blind trial in 1 502 infants either aged less than 6 months and born prematurely (35 weeks of gestation or earlier), or aged under 2 years with a history of
bronchopulmonary dysplasia, has shown that, relative to a placebo,
palivizumab reduces the hospitalisation rates by 5% in absolute values. It does not influence mortality or the need for
mechanical ventilation. (6) Given the lack of relevant trials, we do not know if
palivizumab is effective in infants with immunodeficiency or
congenital heart diseases. We do not know, either, whether the definition of groups at risk used in the only relevant trial is appropriate. (7) No serious adverse effects attributable to
palivizumab were reported in clinical trials. (8) Treatment with
palivizumab is costly.