Background: The American Lung Association Asthma Clinical Research Centers (ALA-ACRC) reported that the inactivated influenza vaccine is safe for patients with asthma and recommended its use to reduce the morbidity associated with infection.
Objective: Because the ALA-ACRC's recommendation would include vaccination of all patients with asthma, including those with severe asthma and first-time vaccinees, we conducted a parallel study to address whether patients with asthma who report bronchospasm after vaccination might be demonstrating a hypersensitivity response to the vaccine.
Methods: Thirty-two adult patients with asthma from the ALA-ACRC cohort were recruited. Subjects were randomly assigned to receive influenza vaccine or placebo and then recorded asthma symptoms and peak expiratory flow rates for 14 days. On day 14, influenza vaccine and egg antigen-induced mononuclear cell proliferation and IFN-gamma, IL-5, and IL-4 production were measured and compared with symptoms.
Results: Increased influenza but not egg antigen-induced mononuclear cell proliferation was present among vaccinated subjects. These responses were unrelated to asthma exacerbations after vaccine. There were no differences in cytokine production in response to either influenza or egg antigen in association with asthma exacerbations.
Conclusions: Episodes of bronchospasm after influenza vaccination do not seem related to hypersensitivity to the vaccine.