HughPickens.com writes Donald McNeil writes in the NYT that this year's flu season may be deadlier than usual because this year's flu vaccine is a relatively poor match to a new virus that is now circulating. "Flu is unpredictable, but what we've seen thus far is concerning," says Dr. Thomas R. Frieden. According to the CDC, five U.S. children have died from flu-related complications so far this season. Four of them were infected with influenza A viruses, including three cases of H3N2 infections. The new H3 subtype first appeared overseas in March but because it was not found in many samples in the United States until September, it is now too late to change the vaccine. Because of the increased danger from the H3 strain — and because B influenza strains can also cause serious illness — the CDC recommends that patients with asthma, diabetes or lung or heart problems see a doctor at the first sign of a possible flu, and that doctors quickly prescribe antivirals like Tamiflu or Relenza. "H3N2 viruses tend to be associated with more severe seasons," says Frieden. "The rate of hospitalization and death can be twice as high or more in flu seasons when H3 doesn't predominate."