live attenuated influenza vaccine

Live attenuated influenza vaccine (LAIV) is a quadrivalent or trivalent intranasal vaccine containing weakened forms of live influenza virus strains. It is designed to induce active immunization for the prevention of influenza disease caused by the specific subtypes and types of influenza A and B viruses included in each season’s formulation. Unlike inactivated flu vaccines administered by injection, LAIV is delivered as a nasal spray. The mechanism involves stimulating an immune response that mimics natural infection without causing disease. LAIV is approved for use in healthy non-pregnant individuals aged 2 through 49 years old. It was first introduced in 2003 and remains the only needle-free seasonal flu vaccine option available in the United States[1][4][5][9]. The most common side effects include runny nose or congestion, sore throat (in adults), and fever (in young children). Contraindications include pregnancy, immunocompromised states, certain chronic conditions (e.g., asthma), severe allergy to eggs or any component of the vaccine[4].

Brand names

FluMistFluMist QuadrivalentFluenz Tetra

Other names

Influenza Vaccine Live, IntranasalInfluenza Virus Vaccine, Live, Intranasalnasal spray flu vaccine