The lethal Type A strain of influenza virus, known as H5N1, first emerged in Hong Kong in 1997 and has since been responsible for the deaths of hundreds of millions of chickens, ducks, and other water fowl, and increasing numbers of mammals. As of February 20th of this year, roughly two hundred people in Southeast Asia, China, Turkey, Iraq, and now India have been infected, most from direct contact with infected birds. Ninety-two are known to have died from the virus.
H5N1 is the most lethal strain of influenza ever seen. Since appearing, it has killed 100 percent of the domesticated chickens it has infected. Over the past one to two years, avian influenza has evolved to become heartier and deadlier, and has jumped the species barrier to kill a wider range of species, including mammals such as tigers, horses, pigs, mice, and humans.
Until recent months, the disease was limited to Asia. Now the virus has been detected in birds in Russia, Europe, the Middle East, and, most alarmingly, in Africa and India. If (and most experts say when) the virus mutates or acquires just a few new genes, it will travel the human world at a deadly velocity. The havoc such a disease could wreak will exceed that of the Spanish flu of 1918-19, which killed at least fifty million people worldwide over a period of eighteen months, including six percent of the U.S. population. Almost no one will have natural immunity, no matter whether they 've received influenza vaccinations previously.
A global avian flu pandemic is by no means a certainty. It is quite possible that nothing will happen. The virus may never acquire the capability for easy human-to-human transmission. Or it may, but then lose some or all of its extraordinary virulence. No one can predict with confidence what H5N1 will do. But the risk of danger is high, and we are quite simply terribly unprepared.
Unlike the typical yearly influenza virus epidemics, it will likely be the young and healthy who suffer the most, because it is not so much the virus that kills, rather the overwhelming immune response of the body against it. In what is known as a cytokine storm, the body quite literally destroys itself. Young healthy bodies with healthy immune systems will mount the most overwhelming immune response, and experience the highest mortality. Most deaths thus far from avian influenza have been in children and young adults.
Aside from the tremendous loss of life, the effect on the global economy would be catastrophic. A pandemic would cause considerable global social and economic disruption. Profound work stoppages would occur. Borders and airports would be closed for months. Trade and travel would virtually cease. The world 's stock markets would undoubtedly crash. Aside from economics, the disease would affect global security, reducing troop strength for all armed forces, UN peacekeeping operations, and civil police worldwide.
A pandemic would quickly overwhelm U.S. hospitals with both the sick and the worried well. Hospitals would also quickly become understaffed, as many medical personnel and their families would be afflicted with the disease. Disruptions in the supply of medications would occur. Many times more people infected with avian influenza would need ventilator care than there exists ventilators in the U.S. How would hospitals deal with the large numbers of patients? How would they make decisions on rationing?
Critical community services would be immobilized, including fire, police, and community government. Workplaces would grind to a halt. Shortages of food and other essentials would occur. Places where people gather - malls, cinemas, theaters, churches, sporting events - would be shut down to limit human spread of the virus. The resulting social breakdown would be unlike anything seen by living Americans.
The U.S. would probably only have about a month or less of warning before a pandemic became widespread. While a vaccine against H5N1 has been developed, there would simply not be enough time to produce it on a large enough scale to immunize the entire U.S. population. Moreover, unlike the usual single yearly vaccination administered in the fall and winter months against the usualy strains of influenza, immunization against avian influenza would require a series of two vaccinations. We simply cannot count on vaccines.
Even if vaccines were to become available, there would also be the dilemma of who to vaccinate. The usual candidates - the very young, the elderly, and the immunocompromised - were actually the ones most likely to survive during the Spanish flu pandemic of 1918-19. As is expected to happen with an avian flu pandemic, it was the young and healthy who suffered the highest mortality. So do we immunize the young and healthy with our limited avian influenza vaccines? Or do we immunize those who society traditionally considers its most vulnerable? And will the majority of Americans wait patiently as those with first priority status - health care workers, police and firefighters, and those in the National Guard and military - are vaccinated?
Only one company, Roche of Switzerland, produces Tamiflu. Its production is slow and difficult, and could not be greatly accelerated in the event of an avian flu pandemic. Countries in the developed world, including Johnny-come-lately the United States, are beginning to stockpile the drug, but if a pandemic were to hit in the next one to two years, there simply will not be enough Tamiflu to go around. Great strife would ensue as the limited supplies of this expensive drug were allocated to those in health care and other essential services. Everyone else, and everyone in the underdeveloped world, would simply be out of luck.
Until the past nine months, the Bush Administration, by spending billions of dollars on what it terms "biodefense", since 9/11 established priorities in inverse relation to actual probabilities. Public health officials have been warning for years that the risk of an avian influenza pandemic, and the potential for massive death and disruption, far exceeds the risks and potentials of bioterrorist outbreaks of anthrax, or smallpox. As one member of the government 's advisory panel on vaccinations said early last year: "It 's too bad that Saddam Hussein 's not behind avian influenza. We 'd be doing a better job".