Active and passive immunisation against respiratory syncytial virus

RSV is a major cause of respiratory illness in infants under 2 years of age . Evidence is accumulating that it is also underestimated as a cause of res piratory infection in adults, the elderly and immunocompromised individuals . Active interventions to control the impact of RSV infection have been ham pered by a lack of understanding of the immune response to RSV in different age groups. A number of different strategies for developing RSV vaccines h ave been pursued, including live attenuated vaccines, genetically engineere d live and subunit vaccines and peptide vaccines with varying degrees of su ccess. The target populations for RSV vaccines include infants, the elderly and women of childbearing age, but the efficacy of different vaccines may differ according to age. Desirable immune responses and immune correlates o f protection to RSV in humans remain uncertain and determining these is cri tical for introduction of any vaccines. Prophylaxis and treatment of RSV in infants using human immunoglobulin cont aining high titres of RSV specific neutralising antibody (RSV-Ig) has shown limited success in different infant populations. Prophylaxis of premature infants with RSV-Ig, particularly those with bronchopulmonary dysplasia, ha s demonstrated limited clinical efficacy against RSV. In contrast, there ar e significant safety concerns for use of this preparation for prophylaxis i n infants with congenital heart disease and no demonstrable efficacy in tre atment of RSV disease in healthy infants. The cost of the preparation will limit use to highly selected infant groups. Production of humanised monoclo nal antibodies to RSV offers another potential passive immunotherapy interv ention for RSV, with increased specific activity and reduced side effects, although its use remains experimental. Copyright (C) 1999 John Wiley & Sons , Ltd.