Preliminary evidence of safety and efficacy of an orally administered, heat-inactivated H5N1 influenza vaccine

Starting from late 2003 multiple outbreaks of highly pathogenic avian influenza type A H5N1 virus have occurred first in Southeast Asia and then in the rest of the world. There is a consensus that influenza pandemics will not fade away as illustrated by H1N1 swine flu outbreak this year. The possibility of a mutation which would cause more deadly virus spread in the human population is of particular concern. The human-to-human H5N1 transmission cases with fatal outcome have already been reported. There is unmet need for an effective vaccine to prevent bird flu outbreaks and potential human pandemic. Immunitor USA Inc is a start-up company which has developed the unique technology that enables the formulation of killed virus into an oral tablet. The vaccine consists of heat- and chemically-inactivated H5N1 virus which was expanded by a standard method in embryonated chicken eggs. The experimental lots of H5N1 oral vaccine have shown promising results in chicken challenge studies. However vaccine's protection in terms of survival as the endpoint was partial and thus further studies are needed to identify optimally effective dose and vaccination schedule. These experiments will serve as proof-of-concept for developing an effective and safe vaccine capable of preventing and perhaps treating influenza virus infection. (C) 2010 Published by Elsevier Ltd.