What is a vaccine adjuvant and will the 2009 H1N1 influenza vaccines that are currently recommended contain adjuvants?
A vaccine adjuvant is a substance that is added to the vaccine to increase the body’s immune response to the vaccine. Vaccine adjuvants will not be used in the United States during the 2009-10 flu season. This includes all of the 2009 H1N1 and seasonal influenza vaccines that will be available for children and adults in both the injectable and nasal spray formulations.