Two randomized trials in the October 8 issue of JAMA examine new vaccination strategies for the prevention and control of avian influenza, often referred to as “bird flu.”

In one study, Mark J. Mulligan, MD, of the Emory University School of Medicine, Atlanta, and colleagues compared the safety and antibody responses (immunogenicity) of different doses of influenza A/Shanghai/2/13 (H7N9) vaccine mixed with or without the MF59 adjuvant (a component that improves immunogenicity and enhances efficacy of inactivated influenza vaccines).

In another study, Robert B. Belshe, MD, of the Saint Louis University School of Medicine, and colleagues examined whether immunologic priming (initial presentation of an antigen to allow antibody responses on revaccination) with vaccine directed toward an older avian influenza H5 strain (A/Vietnam/1203/2004(H5N1) [Vietnam]) might lead to secondary antibody responses to a single dose of a more current H5 avian influenza vaccine (A/Anhui/01/2005 [Anhui]).

In an accompanying editorial, John J. Treanor, MD, of the University of Rochester, New York, writes that these studies “provide important information that expands the available options for confronting pandemic influenza, and may help surmount those obstacles.”