The first live attenuated influenza vaccine (LAIV), FluMist, was approved by the FDA in 2003. A trivalent vaccine administered as a nasal spray, FluMist was approved for use in healthy children and adults between 5 and 49 years of age. This live virus flu vaccine was not recommended for individuals with a history of asthma or other respiratory illness, any underlying chronic illness, including those with immune or metabolic dysfunction, persons with a history of GBS, children or adolescents on aspirin therapy, pregnant women, or anyone with an egg allergy.
Importantly, FluMist was not recommended for people coming in close contact with immunocompromised individuals “because of the theoretical risk that a live, attenuated vaccine virus could be transmitted to the immunosuppressed person and cause disease.” There are documented cases in the medical literature of vaccine virus infection, shedding and transmission with FluMist and other live attenuated virus vaccines.
