Asthma, influenza, and vaccination.

Exacerbations of asthma in children are usually triggered by virus infections. Many different respiratory viruses are associated with these exacerbations, but influenza viruses are frequently associated with those requiring hospitalization and are the only ones for which specific treatment and prophylaxis are available. Current studies have shown that influenza vaccines are safe for patients with asthma. The efficacy of inactivated influenza vaccines in preventing exacerbations of asthma has been questioned. The live attenuated influenza vaccine has been licensed recently in the United States, and studies have shown it to be safe and protective. A direct comparison of the inactivated and live attenuated influenza vaccines in children with asthma demonstrated superior protection by the latter. Live attenuated influenza vaccine, given by nasal spray, is better accepted by children for annual vaccination and is easier to administer. Universal vaccination of all children in school-based clinics will facilitate control of epidemic influenza and provide an infrastructure for control of future influenza pandemics.