of seasonal flu. The modifiability could also allow it to be quickly customized as a vaccine against a pandemic influenza if one were to emerge. In light of the Global spread of H5N1 advance preparation to reduce human mortality in the event of an H5N1 pandemic has begun. Modifying FluMist to serve as a specific human H5N1 vaccine is among the measures studied. In June 2006, the National Institutes of Health (NIH) began enrolling participants in a Phase I H5N1 study of an intranasal influenza vaccine candidate based on MedImmune's live, attenuated vaccine technology. In September 2006, the National Institute of Allergy and Infectious Diseases (NIAID) reported that inoculation with a live attenuated influenza vaccine modified to present the surface antigens of certain H5N1 variants provided broad protection against other H5N1 variants in the mouse and ferret models. Attenuated live viruses were found protective against H5N1 in mice and chickens in a 2009 study. Although early work is focusing on the looming H5N1 threat, the CDC team led by Kanta Subbarao and others intends to eventually prepare and store surface antigens for all known strains of influenza, ready to be grafted onto the base attenuated FluMist core virus whenever a pandemic threat might emerge. "Several trials have reported that LAIVs can boost virus-specific CTLs as well as mucosal and serum antibodies and provide broad cross-protection against heterologous human influenza A viruses." (58, 59) "[V]accine formulas inducing heterosubtypic T cell–mediated immunity may confer broad protection against avian and human influenza A viruses." In September 2009, a live attenuated intranasal vaccine for the novel H1N1 influenza virus was approved. References External links 2009 swine flu pandemic AstraZeneca brands Influenza vaccines Live vaccines