CDC Panel Urges Extending Flu Vaccine Coverage for Kids

The virus strain most common in the United States right now is the influenza A H3N2 strain, and it's a strain not included in this year's vaccine. Also, this year's vaccine is not well-matched against influenza type B.

Complicating matters, some of this year's influenza type A virus is showing resistance to the antiviral drug Tamiflu. Overall, 8.1 percent of the influenza type A viruses tested by the CDC were resistant to Tamiflu. In past years, less than 1 percent of the viruses have been resistant to the drug.

Last week, the U.S. Food and Drug Administration selected the influenza strains that will make up the 2008-09 flu vaccine. Following the lead of the World Health Organization, the FDA is including the new flu strains Brisbane/10, a version of the H3N2 flu; a second new Type A strain known as H1N1/Brisbane/59; and a newer Type B/Florida strain.

But according to one expert, even the best planning may not result in a perfect vaccine.

"You have to make a decision about what will be in the vaccine in advance," said Dr. John Treanor, a professor of medicine, microbiology and immunology at the University of Rochester Medical Center in Rochester, N.Y. "It takes six to eight months to make the vaccine after you've chosen the strains.

"But the reality is that new strains emerge after that decision is made. So, you could be wrong," Treanor said.

More information

For more on flu vaccine, visit the CDC.

SOURCES: Richard Kanowitz, president, Families Fighting Flu, New York City; John Treanor, M.D., professor of medicine, microbiology and immunology, University of Rochester Medical Center, Rochester, N.Y.; Feb. 27, 2008, news release, National Foundation for Infectious Diseases