Pandemic reality check

What can and can't be done to protect against H1N1

By John M. Barry

This month, the World Health Organization finally declared that the H1N1 virus has become pandemic. It reported a big jump in cases and fatalities since June 19. How many people this virus will sicken and kill depends, ultimately, on three things: the virus itself; the impact of what are known as non-pharmaceutical interventions; and the availability and effectiveness of a vaccine.

The virus will be the most important factor. Influenza is one of the fastest-mutating organisms in existence, which makes it unpredictable. There have been four pandemics that we know about in some detail: 1889-92, 1918-20, 1957-60 and 1968-70. All four followed similar patterns: initial sporadic activity followed four to eight months later by waves of widespread illness.

In all four pandemics, lethality changed from wave to wave — sometimes increasing, sometimes decreasing. It’s impossible to know what will happen this time.

For a mild pandemic, we may not need to take steps beyond washing hands, exercising “cough etiquette” and keeping the sick at home. But if the virus increases its virulence, other measures, such as closing schools, urging people to telecommute and even banning public meetings, could mitigate the impact.

The most important intervention is, of course, a vaccine. Because influenza mutates so rapidly, a new vaccine has to be made each year just for seasonal flu. Vaccines for most diseases approach 100 percent effectiveness, but a good flu vaccine is 70 percent effective.

Supply is another problem. In a best case, enough vaccine for the entire U.S. population could be available by October. However, only about 30 percent of the supply will be made in the United States. The more virulent the virus, the more likely it is that foreign governments will refuse to allow export of the vaccine until their own populations are fully protected.

The bottom line? Little can be done in the short term beyond exerting diplomatic pressure to guarantee that foreign governments allow manufacturers to honor contracts to export vaccine. In the medium term, sustained investment could make it possible to produce massive amounts of vaccine in a few weeks. In the long term, we need a vaccine that works against all influenza viruses. Enough work has been done to suggest that this Holy Grail is achievable. Had influenza been taken seriously for the past 30 years, we would probably have one by now. No matter what happens over the next year or two, that’s one history lesson we need to learn.

(Barry is a distinguished scholar at the Center for Bioenvironmental Research at Tulane and Xavier Universities and the author of “The Great Influenza: The Story of the Deadliest Pandemic in History.” This essay first appeared in the Washington Post.)

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