The humanized monoclonal antibody Palivizumab specific for an epitope in the A antigenic site of the F protein of RSV was
approved in Japan for prevention of severe RSV infections in premature babies, bronchopulmonary dysplasia and congenital heart disease, but at that time other high risk groups such as patients with immunode ficiencies, neuromuscular disorders, or chromosomal abnormalities were not included.