New quadrivalent flu mist vaccine for children, adults

The first influenza vaccine to contain 2 strains of influenza A virus and 2 strains of influenza B has been approved by the US Food and Drug Administration for use in healthy children aged 2 years and older and adults to age 49 years.

The new quadrivalent intranasal vaccine contains weakened forms of the live influenza viruses and is administered as a spray into the nose. The addition of the second influenza B strain increases a person's overall protection against seasonal influenza infection.

Three clinical studies involving 4,000 children and adults were conducted for safety and effectiveness of the quadrivalent vaccine and demonstrated that immune responses were similar between the new formulation and the older trivalent intranasal vaccine previously approved for children and adults.

The Centers for Disease Control and Prevention recommends that all persons aged 6 months and older be vaccinated annually against seasonal influenza. Attenuated intranasal influenza vaccine should not be administered to children younger than 2 years.