Respiratory syncytial virus (RSV) is the leading cause of serious lower respiratory infection (ALRI)-related hospitalization in children worldwide, and a source of morbidity and mortality in high-risk adults. There are strong associations between RSV, persistent wheezing and childhood asthma. Despite extensive research, no effective treatment is available aside from supportive care. The trial of a formalin-inactivated RSV vaccine in the 1960s resulted in priming the severe illness upon natural infection. Palivizumab, a monoclonal antibody approved for RSV prophylaxis in high-risk infants, has only moderately decreased hospital admissions due to RSV infection. Live-attenuated, vector, and protein-based vaccine candidates are being investigated in many clinical trials. Developing a vaccine remains challenging due to finding the right balance between adequate immunogenicity and attenuation of vaccine. Here we review the clinical significance of RSV in infants, young children, high-risk adults, elderly population, pregnant women; clinical manifestations and consequences of RSV infection; the pharmacologic strategies currently available, the current stages of RSV vaccine clinical trials, different strategies, and major hurdles in the development of an effective RSV vaccine.
Part of the book: The Burden of Respiratory Syncytial Virus Infection in the Young