FLUAD is an influenza vaccine specifically designed to protect against the flu virus in older adults, typically recommended for those aged 65 and older. It is a trivalent vaccine, meaning it is formulated to protect against three different flu viruses: two influenza A virus strains and one influenza B virus strain. What sets FLUAD apart from other flu vaccines is the addition of an adjuvant called MF59, a substance that enhances the body's immune response to the vaccine. This feature makes FLUAD particularly effective in the elderly, a group that often has a weaker response to traditional flu vaccines. Administered as an injection, usually into the muscle of the upper arm, FLUAD is part of the annual vaccination program aimed at reducing the incidence of flu and its complications among the most vulnerable populations.