The first human trial of a DNA vaccine designed to prevent H5N1 avian influenza infection began late last month, when the vaccine was administered to the first volunteer at the National Institutes of Health (NIH) Clinical Center in Maryland in the US.
Scientists from the Vaccine Research Center (VRC) at the National Institute of Allergy and Infectious Diseases (NIAID), one of the NIH Institutes, designed the vaccine.
The study will involve 45 volunteers between the ages of 18 and 60. Fifteen will receive placebo injections and 30 will receive three injections of the trial vaccine over 2 months and will be followed for 1 year. NIAID researchers will measure immune responses to the vaccine, assess its safety, and compare its potency to more traditional vaccine approaches.
DNA-based vaccines contain only portions of the influenza virus' genetic material, unlike conventional flu vaccines, which are developed by growing the influenza virus in hens' eggs and then weakened or killed before being administered as a vaccine. The DNA vaccine works by instructing human cells to make proteins that act as a vaccine against the virus.
VRC Director Gary Nabel and his colleagues previously have shown the DNA vaccine approach to be effective against influenza viruses in animal models, including highly pathogenic viruses such as the H5N1 avian influenza strain and the H1N1 virus that caused the deadly 1918 pandemic.
"An effective H5N1 influenza vaccine would provide a potentially life-saving advance against a global health threat," notes NIAID Director Anthony Fauci. "More broadly, development of this DNA vaccine technology has the potential to improve our production capacity for vaccines to prevent seasonal influenza and other diseases."
"This vaccine is aimed at newer strains of the H5N1 virus that currently pose a threat in Indonesia and represents an example of our ability to respond to shifting viruses with modern technology," says Dr Nabel.
The World Health Organisation reports that 261 humans have been infected with the bird flu virus, resulting in 151 deaths.