The study's findings, coupled with the apparent staying power of the H5N1 strain (it has been circulating since 1997) and the fact that many experts say an influenza pandemic is overdue (historically such outbreaks occur about every 30 years, and the last occurred 37 years ago) contribute to the urgency in preparing for a pandemic.
That urgency is apparent in the flurry of government activity in response to the pandemic threat. The U.S. State Department recently hosted a meeting of senior health officials from nearly 70 countries to address the need for improved communications and efforts to prevent a pandemic. And President Bush has met with vaccine makers to urge increases in flu vaccine production.
Further, the Bush administration and Congress are considering spending billions to stockpile the antiviral drug Tamiflu, legislation has been introduced that would further ramp up vaccine production and pandemic preparedness, and the National Institute of Allergy and Infectious Diseases has teamed with MedImmune Inc. to develop and manufacture new influenza vaccines, including vaccines against high-priority strains such as H5N1.
But some experts have suggested that H5N1 does not confer a pandemic threat, saying that if it was going to develop the ability to efficiently transmit between people, then it would have done so by now, and that because the bird flu is distantly related to earlier flu viruses, much of the population already has some level of immunity.
Whether or not H5N1 becomes pandemic, preparing for a potential pandemic is warranted and worthwhile, say experts.
“Even if it does not materialize, the planning and development of effective interventions will provide the necessary preparations in the event that another avian strain jumps the species barrier or a known human pathogen like H2N2, to which large segments of the population lack immunity, reemerges,” John G. Bartlett, M.D., of Johns Hopkins University, Baltimore, and Frederick G. Hayden, M.D., University of Virginia Health Sciences Center, Charlottesville, Va., stated in a recent editorial (Ann. Intern. Med. 2005;143:460–2).
Preparations would also enhance the nation's ability to cope with annual epidemics and their substantial toll. Widespread vaccination and use of antiviral drugs could provide the foundation for responding to the next pandemic, thus warranting the stockpiling of antiviral agents, they wrote.
Giving Regular Flu Vaccine May Help
The most effective thing individual physicians can do is vaccinate patients against the currently circulating influenza strains, Dr. Poretz said.
Such vaccination will address the immediate concern of influenza outbreaks in the United States, and, according to guidelines from the WHO, could be useful for preventing co-infection with H5N1 and a human influenza strain.
According to the WHO, doing so will decrease the opportunity for genetic reassortment of the avian H5N1 strain with genes from a human (H1 or H3) strain and thereby reduce the likelihood that a novel pandemic strain will emerge from the current situation in Asia.
If an avian influenza pandemic does occur, diagnosis could prove quite difficult, because the symptoms of H5N1 are similar to those of “regular flu,” Dr. Campos-Outcalt said.
Communication and surveillance will be the cornerstones of effective management, he added. This is where education for and by physicians becomes important.
Physicians need to stay up to date, because so much is unknown about how patients would present in the event of a pandemic. And physicians need to educate patients about the preventive measures that will become imperative should available vaccines and antivirals prove ineffective for the pandemic strain.