Advances in the vaccination of the elderly against influenza: role of a high-dose vaccine.

On 23 December 2009, the US FDA approved Fluzone® High Dose, a high-dose formulation of the trivalent inactivated influenza vaccine, for prevention of influenza in people 65 years of age and older. As it was approved via an accelerated process designed to allow expeditious availability of safe and effective products with promise to treat or prevent serious or life-threatening diseases, the manufacturer is required to conduct further studies to demonstrate effectiveness. Although these studies are underway, a recently completed randomized, controlled trial demonstrated that this vaccine, containing four-times more hemagglutinin than standard-dose inactivated influenza vaccines, can produce an enhanced immunologic response in subjects of 65 years of age and older, while maintaining a favorable safety profile. This article introduces the vaccine, presents currently available safety and immunogenicity data, discusses current recommendations for use, and proposes what we can expect in the coming years.