The American Association for the Advancement of Science hosted a panel discussion on H1N1 flu last week. For such a frightening subject, the discussion was strangely encouraging. Yes, the flu (if not this one, then some other strain) could kill us all. It has already infected an estimated one million people (including the actor who plays Ron Weasley). But as Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said at the event, the world has been preparing intensively for a flu pandemic for the past few years, and "we now have a window of opportunity" to fight this outbreak.
Whenever a new flu virus emerges, "the specter of 1918/1919 hovers over every discussion of the problem," said Harvey Fineberg, president of the Institute of Medicine. That flu pandemic killed at least 25 million and perhaps as many as 100 million people worldwide, including 500,000 to 750,000 in the United States, when its population was a third of what it is today.
Would a similar virus be as dangerous today? Probably not: many of the deaths in 1918 and 1919 were due to secondary bacterial infections that today would be treated with antibiotics. There were no anti-virals or intensive care units. On balance, Fauci concludes, there would have been fewer deaths in 1918 if people had had access to today's medicine, "but it still would have been a terrible pandemic." On the other hand, today we have dense cities, drug-resistant bacteria and routine global transportation that can bring contagious (even if not yet symptomatic) human flu vectors to new continents in a matter of hours.
Aside from a few lesser pandemics in the 20th century, flu has become a routine seasonal disease. "We've been saying for some time," Fauci said, "that we're not doing a good job of taking seasonal flu seriously." Two recent events made fighting flu more urgent: in 2004, one of the companies that makes flu vaccine had contamination problems, and half of the United States' expected supply of vaccine was lost. More ominously, bird flu, H5N1, started infecting people in Southeast Asia. About 450 people have been diagnosed with the disease, and half of them have died. That virus doesn't spread easily from person to person—at least not yet—but its deadliness prompted the CDC, FDA, NIH and WHO to prepare to make an emergency vaccine if bird flu ever did become easily communicable.
Now all those preparations are paying off. "For the past several years, we've been investing in preparedness, surveillance, research in vaccines, response at the state level, the manufacturing base," said Assistant Surgeon General Anne Schuchat. The CDC isolated the new H1N1 virus right away and provided manufacturers with a "seed strain" to serve as a template for a vaccine. A vaccine is being prepared in pilot lots and will be tested in clinical trails soon. "The process of making a vaccine is at full speed," says Fauci. "If all goes well, we should be prepared to vaccinate in the fall."
In the meantime, public health officials are monitoring flu outbreaks in the Southern Hemisphere, where flu season is just beginning. (Flu viruses circulate more efficiently in cold, dry air, especially when people spend a lot of time in enclosed spaces.) They're watching whether the virus mutates, whether it afflicts certain age groups disproportionately, how to deal with outbreaks in schools, and how deadly it is. "Anytime you talk about influenza," said Fauci, "you have to prepare for the unpredictable."