Trudeau Institute discovers how FluMist elicits protection

New research from the USA-based Trudeau Institute may help to explain why live attenuated influenza vaccine (LAIV), sold by AstraZeneca subsidiary MedImmune as FluMist, elicits protection. The research is published in this month's issue of Vaccine. The journal article is titled Live attenuated influenza vaccine (LAIV) impacts innate and adaptive immune responses and was authored by Trudeau Institute scientist Laura Haynes and colleagues.

"Our research specifically examines how the vaccine, which is commonly known as FluMist, elicits protection," said Dr Haynes, adding: "Influenza infection normally induces a massive inflammatory response in the lungs that leads to significant illness and increases the susceptibility to secondary bacterial infections. The most efficient way to prevent influenza infection is through vaccination. To date, the mechanism of how FluMist induces protection has been unclear. Our study demonstrates that this vaccine works by inducing a very early non-specific immune response in the lungs in a mouse model of influenza infection."

The very early non-specific immune response sets the stage for the early influx of virus-specific immune cells, which are necessary for viral clearance. Importantly, this immune response is protective against both matching and non-matching influenza strains, therefore it could provide a level of protection in the case of a newly emergent influenza strain.