Public health officials who warn of a looming flu pandemic cite as cause for worry recent Asian cases in which influenza viruses normally restricted to aquatic birds were transmitted to humans. Fortunately, in each case, the virus stopped short of spreading from person to person. But the growing fear is that, if a bird influenza virus became transmissible among people, the new strain would be unrecognized by the human immune system, leading to widespread infection, illness and death. Three such 20th-century pandemics occurred in 1918, 1957, and 1968.
Kanta Subbarao, M.D., senior investigator in the Respiratory Viruses Section of the Laboratory of Infectious Diseases, headed by Brian Murphy, M.D., and Robert Purcell, M.D., is working to prevent the worst case scenario from occurring. She and others in the lab are creating a vaccine for each of the 16 hemagglutinin proteins found in bird strains of influenza A including several subtypes that currently are not transmissible to humans. In this way, should a strain containing any one of these proteins make the jump to people, a vaccine could be prepared rapidly. The live, attenuated vaccines would be given as a nasal spray.
Heading the list of vaccines to be developed are those for the proteins H5, H7, and H9, which is in keeping with priorities set by the World Health Organization. Once the pandemic vaccines have been developed, they will be tested—first in animals and later in humans—for safety and the ability to spur an immune response.
A vaccine against H9N2, developed by Dr. Subbarao and her colleagues, was tested in a clinical trial in the summer of 2005 at the Johns Hopkins Bloomberg School of Public Health.
In September 2005, NIAID announced a cooperative research and development agreement between the Laboratory of Infectious Diseases and MedImmune, of Gaithersburg, Maryland, to work on developing live, attenuated vaccines against flu virus strains with pandemic potential.
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Last Updated August 12, 2010