Swine Flu Virus Not Mutating, Making Vaccine a Good Match

Sept. 26 -- FRIDAY, Sept. 25 (HealthDay News) -- The genetic makeup of the H1N1 swine flu continues to remain stable, making the forthcoming vaccine a "good match" for the virus, U.S. health officials reported Friday.

And, though the virus continues to spread throughout all 50 states, most cases are mild to moderate, much like the regular "seasonal" flu, the officials said.

"H1N1 is spreading widely throughout the U.S., particularly in the southern states, but in most of the country H1N1 activity is now widespread," Dr. Thomas R. Frieden, director of the U.S. Centers for Disease Control and Prevention, said during an afternoon news conference.

As was the case during the outbreak in the spring, when the H1N1 swine flu first surfaced in the United States and Mexico, the disease continues to affect mostly young adults and children, Frieden said.

And though most cases are mild to moderate, the swine flu is "no picnic," he noted. When you get it, you can have several bad days, "and in severe cases, it can even put you in the hospital," he said.

Frieden said that testing shows no genetic changes in the H1N1 virus, which he described as "really good news."

"It means that the vaccine that we have coming off the production line shortly is a very good match -- in fact, an excellent match -- with the virus that continues to circulate, which suggests it is likely to be very effective in preventing illness," he said.

This also suggests that "the disease is not likely to become deadlier," Frieden said. But, he added, flu is one of the most unpredictable infectious diseases so forecasts about what might happen aren't foolproof.

As for reducing your chances of becoming infected, the advice remains the same: Get vaccinated when the vaccine becomes available next month, wash your hands frequently, cover your mouth when coughing and sneezing, and stay home if you are sick.

The vaccine for the H1N1 flu will be available in large quantities by late October, Frieden said. Some vaccine, in the form of a nasal spray (FluMist), will be available the first week of October.