People who have severe asthma may be particularly at risk for infection with the 2009 H1N1 influenza virus. A report published in 2004 suggested that some people who took high doses of glucocorticoids to treat their asthma may receive less protection from influenza vaccines against some strains of influenza. Early in the 2009 H1N1 flu outbreak a CDC review of hospital records found that people with asthma have a four-fold increased risk of being hospitalized with infection compared to the general population.

The study will enroll approximately 350 people with mild, moderate and severe asthma. Participants will be organized into two groups: those with mild or moderate asthma and those with severe asthma. Half of the participants in each group will receive a 15-microgram dose of vaccine, and the other half a 30-microgram dose. Three weeks later, each participant will receive a second dose of the same amount. The strength of the immune response induced by the vaccine will be determined in blood samples by measuring the level of antibodies against 2009 H1N1 flu virus.

Safety data will be collected and examined throughout the course of the study by trial investigators and by an independent safety monitoring committee. Participants will be monitored for any side effects they may experience because of the vaccine, as well as asthma attacks that occur during the study period.

The vaccine to be used in the trial, manufactured by Novartis, contains inactivated 2009 H1N1 influenza virus and therefore cannot cause anyone to become infected with the virus.

Source: NIH/National Institute of Allergy and Infectious Diseases