Low accrual(4 completed subjects over 2 months)& inconclusive nasal wash assays.

The Live-Attenuated Influenza Vaccine (LAIV), also known as FluMist, has been shown to be effective in children but less effective in adults. Our hypothesis is that this relative failure is due to adults having enough anti-flu IgA antibody in nasal secretions to neutralize the weakened vaccine virus.

This is a VA-based study to evaluate serum and nasal wash antibody responses to seasonal LAIV of healthy Veterans and VA employees between the ages of 20 and 49 years old.

Specific Aims

1. The primary aim of the study is to evaluate whether people with high mucosal IgA antibodies against flu have a lower immune response to the seasonal LAIV.
2. The secondary objective is to determine whether the nasal wash viral neutralization data predicts LAIV immunization failures.

Inclusion Criteria:

• Medically eligible healthy men and women between the ages of 20 to 49 years old.

Exclusion Criteria:

• A medical condition that places them at high risk for complications from influenza, including those with chronic heart or lung disease, such as asthma or reactive airway disease; people with medical conditions such as diabetes or kidney failure; or people with illnesses that weaken the immune system, or who take medications that can weaken the immune system.
• A history of Guillain-Barré Syndrome that occurred after receiving influenza vaccine
• Currently pregnant
• Have a severe allergy to chicken eggs or who are allergic to any of the nasal spray vaccine components
• Have had flu within the current flu season.
• Have had a flu vaccine within the current flu season.
• Have close contact with someone whose immune system is so weak they require care in a protected environment (such as bone marrow transplant unit).

This study was terminated due to poor enrollment. Analyses were not conducted due to inconclusive nasal wash samples.