Bird-flu watching

President Bush met with U.S. vaccine developers on Oct. 7, not long after reading a gruesome history of the 1918 Spanish flu pandemic. The 500-plus page book by John M. Barry tells how 40 million of the world's youngest, healthiest people died horrifically, bleeding from their ears and noses and turning blue from lack of oxygen. The book also skewers military and government officials who ignored warnings about poor public health conditions in barracks and cities.

At the meeting, President Bush reportedly urged U.S. drug companies to increase their capacity to produce a vaccine for a new strain of avian influenza inching west across the globe. European Union members met Oct. 18 after the virus appeared in poultry on a Greek island in the Aegean Sea. Its emergence in Greece, the first EU member nation affected, followed cases in poultry in Turkey and Romania. Though more than 60 people have died of the virus in Asia, no human cases have been reported in Europe.

Scientists frequently compare the new bird flu to the 1918 flu because of the severe disease it causes in humans who catch the virus from poultry. Across the airwaves, experts continue to reiterate their worst fear that the avian flu will mutate into a strain easily passed from human to human and explode into the dreaded "P" word: a pandemic.

While such dire forecasts contribute to public fears about bird flu, they do little to educate the public about the real probability of a flu pandemic and the important role the public plays in controlling one.

A flu pandemic occurs about once every 50 years when a new strain of flu that has never infected humans emerges. The last major pandemic struck in 1968. Scientists have no way to calculate the probability that the current bird flu strain, H5N1, will mutate into a pandemic strain. If it does not, they are sure another strain will soon take its place as the next pandemic.

"H5N1 poses a very unique threat, but it's not the only threat to us in terms of pandemic influenza," said Dr. Andrew Pekosz, associate professor of microbiology at Washington University.

In the book Mr. Bush read, The Great Influenza, Mr. Barry, who has written several historical chronicles of disease and disaster, describes influenza as a mutant swarm that evades the immune system by hiding out in human cells and continually changing its genetic code. Vaccine makers face the constant challenge of staying a step ahead of the mutant swarm. They often do not know how effective a vaccine will be until its release.

The United States is testing a vaccine against the avian strain of H5N1 that might afford some protection against a mutated, pandemic version of the virus. Still, drug companies cannot start producing a true pandemic vaccine until they know what that strain of virus looks like; in which case, the pandemic would already be underway.

Further complicating matters is the large dosage of H5N1 vaccine-eight times more than a regular flu shot-needed to be effective, Dr. Pekosz noted. In a pandemic, he said, members of the public should not expect to get vaccinated unless they are involved in health care or public works like electricity production. "Right now, we just can't make enough," he said.

The World Health Organization also emphasizes that no vaccine can stop a pandemic. "Although it is not considered feasible to stop the spread of a pandemic virus, it should be possible to minimize its consequences through advance preparation," states the WHO Global Influenza Preparedness Plan. That preparation means capitalizing on the major advantage today's world has over 1918: public health. The Spanish flu struck at the height of World War I, when the world's overcrowded barracks and trenches acted like a pipeline carrying the disease into unsuspecting communities.

The WHO plan suggests myriad public health measures, from hand washing to school closings. It also recommended stockpiling supplies of the anti-viral drug Tamiflu, a remedy whose effectiveness against past cases of bird flu researchers have found to be questionable. The Bush administration is expected to release its flu pandemic preparedness plan in the next few weeks. The New York Times obtained a leaked version of the plan, which the newspaper said laid out worst-case scenarios and suggested government responses to a pandemic. But the risks of an H5N1 pandemic are over-hyped, argues Marc Siegel, New York University professor and physician. "We tend to over-personalize the news and ramp up our expectation of danger beyond the actual risk," he said. Scientists can still say "if" about H5N1, but they agree the emergence of some kind of flu pandemic is a matter of "when."

Today's world also has the advantage of instant communication, but communication can only help to the extent people are willing to comply with orders. While not as convenient as a vaccine, they are just as important, Dr. Pekosz said.

"When those public health measures are announced, it's really important to do them."