Swine Flu Virus Not Mutating, Making Vaccine a Good Match

By Steven Reinberg
HealthDay Reporter

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.

But FluMist is not for everyone. It's not recommended for children younger than 2 years; for people with chronic medical conditions such as heart disease, kidney disease and diabetes; for pregnant women; or for people older than 49. Children and pregnant women are among those at greatest risk for complications from the H1N1 flu, according to the CDC.

For people 10 and older, only a single dose of the H1N1 vaccine will be needed, Frieden said, adding that "there is every reason to believe that this vaccine will be safe."

He said it's important that people with underlying medical conditions -- such as diabetes, heart disease and respiratory problems -- get vaccinated. Other priority groups include pregnant women, health-care workers and people who care for infants and children.

To get children vaccinated, there will be school vaccine clinics, "something we don't usually do in a normal flu season," he said.

Frieden also urged people to get a flu shot for regular seasonal flu now. Supplies are plentiful.

Antiviral medications such as Tamiflu should be used carefully, Frieden said. "People who need to be treated are people who have underlying conditions or are severely ill," he said. "It should not be used for prevention, and it should not be used for most mild, average cases. That way, people who really need it will have enough to go around, and we won't have an increased risk of resistance."

Despite health officials' recommendations that Americans get vaccinated against the H1N1 swine flu, only 40 percent of parents plan to have their children vaccinated, even though the flu has become more active now that kids are back in school, a new survey found.

Among the parents who don't plan on having their children vaccinated against H1N1 flu, 46 percent said they're not worried about their children getting swine flu and 20 percent said they believe the flu isn't serious, according to the C.S. Mott Children's Hospital National Poll on Children's Health, which surveyed 1,678 parents from Aug. 13 to 31.