RSV consists of two antigenic subtypes, A and B.
Subtype B is characterized as the asymptomatic strains that of which the majority of individuals experiences.
The more severe illnesses and which usually predominate during outbreaks are associated with subtype A strains(8).
RSV was determined to be the leading cause of lower respiratory tract infections particularly in young infants. The severity of the disease is very diverse ranging from mild cold symptoms to severe and life-threatening. It’s the leading cause of pneumonia and bronchiolitis in infants. It may cause mortality or morbidity in the elderly as well as immunodeficient individuals. It is the most common pathogen leading to hospitalization in young children up to the age of 5. Approximately two thirds of infants are infected with RSV within their first year and 90% have been infected by the age of 2.