RSV (respiratory syncytial virus) has been recognized as a significant cause of respiratory illness in all age groups. It is highly infectious and the most common cause of lower respiratory tract infection in infants and children worldwide, resulting in a high number of hospitalizations. RSV infections are also a serious health concern in the elderly and in adults with cardiopulmonary disease.
According to estimates from WHO, RSV infects more than 64 million people globally each year and causes a similar number of deaths as influenza, yet unlike influenza, there is no vaccine to prevent RSV.
There are only two subtypes of RSV, A and B, which are typically present either simultaneously or alternately during yearly epidemics.