The large number of serotypes makes the development of an effective vaccine unlikely. Nearly 90 percent of rhinovirus serotypes have intercellular adhesion molecule-1 as a common receptor. Acid sensitivity and optimal growth at 32 to 34 C are thought to account for this molecule's restricted replication in the nasal mucosa and possibly the large airways. Rhinovirus causes approximately 40 percent of colds in adults each year and up to 80 percent during peak season. Immunity to rhinovirus is type specific and relatively solid after infection, although reinfection can occur.
Rhinoviruses cause infections year-round but are most prevalent in early fall and late spring.
The relative importance of fomite spread and aerosols in rhinovirus transmission is uncertain under natural conditions. The incubation period of rhinoviruses averages about two days. Rhinovirus colds vary in severity from mild episodes characterized by one to two days of coryza or scratchy throat to illnesses with profuse rhinorrhea, pharyngitis, and bronchitis. Outbreaks of rhinovirus infection are associated with more frequent lower respiratory tract illness in institutionalized adults and with bronchospasm and protracted cough in those with preexisting airway disease. Rhinovirus infections are associated with acute sinusitis, otitis media, exacerbations of chronic bronchitis and asthma, and lower respiratory tract disease in infants and young children.