Officials in Vietnam announced Tuesday that a 35-year-old man and a 14-year-old girl had tested positive for a potentially lethal bird flu virus known as H5N1, which has been spreading among chickens and other birds in Southeast Asia. These are the latest cases in what many public health officials worry is the possible beginning of a worldwide outbreak of a deadly new flu.
The virus has now killed millions of birds and infected more than 50 people, killing three out of every four patients. Now there is evidence that in rare cases it can spread from person to person.
"The virus is clearly going in what we call the wrong direction for us," says Dr. Anthony Fauci, director of the National Institute of Allergies and Infectious Diseases.
The big concern is that the virus will mutate even more until it reaches the point that it spreads easily from person to person. The result would be what scientists call a pandemic — a worldwide outbreak of a virus to which people have no immunity.
That situation is what happened in 1918 when 20 million to 50 million people around the world died from a new strain of flu that also originated in birds. Experts agree there will be another flu pandemic, but no one knows when.
"It absolutely dwarfs all other public health problems that we can imagine," says Dr. Michael Osterholm, director of the Center for Infectious Disease Research and Policy.
To prepare for such an event, the federal government has already purchased two million doses of a vaccine made from a bird flu virus taken from a man who died in Vietnam. Tests haven't yet begun to determine whether it is safe or effective.
"If you wait for that, you are so far behind the eight ball it would be almost impossible to catch up," says Fauci.
Others point out that even 2 million doses is a fraction of what might be needed. And vaccine manufacturers, which have had plenty of problems of their own in the past year, would have trouble meeting the real demand.
"We've got a long ways to go yet to be able to even cover our population in a timely manner, let alone the rest of the world," says Osterholm.
As additional preparation, the United States has stockpiled about 2.3 million doses of antiviral medicine. But other countries have much more: Britain 14 million doses, France 13 million and Canada more than 8 million.
Who would get the scarce drugs and vaccine in the event that a flu epidemic spread to the United States? The Centers for Disease Control and Prevention has asked a group of ethicists to try to decide.