A double-blind placebo-controlled study of the effect of influenza vaccination on airway responsiveness in asthma.
Influenza A infection may cause severe exacerbations of asthma with increased airway responsiveness and airflow obstruction (1). Annual vaccination against influenza is therefore recommended for patients with asthma by the Chief Medical Officer of the Department of Health. However, some patients report exacerbations of their asthma, apparently related to influenza vaccination, and there is reluctance to adhere to the recommended vaccination policy (2). We therefore studied the effect of a current subunit vaccine on symptoms, medication use, spirometry and airway responsiveness in patients with stable asthma.