FRIDAY, Jan. 11, 2013 (HealthDay News) -- Flu continues its march across the United States, with 47 states now reporting widespread influenza activity, up from 41 last week, federal health officials reported Friday.
However, flu has begun to subside in some areas, especially in the Southeast, where it showed up first.
The U.S. Centers for Disease Control and Prevention also reported that the current vaccine was found to be about 60 percent effective in warding off illness, which means it offers "moderate" protection from the flu, which is particularly severe this season.
Flu activity is worsening as peak flu season -- usually late January -- nears, CDC officials said at a news conference.
"Most of the country has seen, or is seeing, a lot of flu, and this may continue for a number of weeks," said CDC director Dr. Thomas Frieden.
"We are continuing to see influenza activity elevated in most of the U.S.," he added. "It may be decreasing in some areas, while other areas in the country, particularly the West, appear to be on the upswing."
Two more children died from flu complications last week, bringing the total to 20 youngsters this season, Frieden said.
The CDC does not keep an up-to-date tally of adult deaths.
Although flu remains at epidemic levels, the rate of doctor's visits for flu have dropped, Frieden said. "That's the trend," he said, adding that "the next week or two will show whether we have, in fact, crossed the peak or whether we'll see a resumption of increase."
Twenty-four states and New York City are reporting a high level of flu, down from 29 states last week. Sixteen states are reporting moderate levels, up from nine a week ago, Frieden said.
It's still not too late to get a flu shot, the CDC said. Researchers who evaluated the flu vaccine in a study of more than 1,000 children and adults found it 62 percent effective in warding off flu, according to a report in the Jan. 11 edition of the CDC's Morbidity and Mortality Weekly Report.
"The take-home message is that the flu vaccine is moderately effective this year, and people who are vaccinated have about a 60 percent lower risk of getting the flu compared to someone who is not vaccinated," Dr. Edward Belongia, an epidemiologist and a lead researcher on the report, said in a statement Friday. "It's a safe vaccine that can help prevent the flu and its complications in both children and adults," he said.
The CDC recommends that everyone 6 months and older get vaccinated. The agency urges people at higher risk for severe disease -- including young children, pregnant women, anyone with a chronic health problem and the elderly -- to get the vaccine.
However, spot shortages of vaccine and the antiviral drug Tamiflu may make preventing and treating the flu more difficult for some people.
The pharmaceutical company Roche is reporting shortages of the liquid form of Tamiflu, according to USA Today. Liquid Tamiflu is often given to children unable to swallow pills.
U.S. Food and Drug Administration spokeswoman Sarah Clark-Lynn told The New York Times that the FDA is working with the company that markets Tamiflu, Genentech, to increase supplies. The agency is also telling pharmacists that in emergencies they can compound the adult Tamiflu capsules to make liquid versions for children.
Meanwhile, drug maker Sanofi is reporting a shortage of Fluzone vaccine, according to published reports.
Sanofi has said it has produced all the vaccine it can for this year and has started work on next year's vaccine.
"The FDA is aware of reports of some spot shortages of influenza vaccine," FDA spokeswoman Rita Chappelle said. "At this time, we believe that there is an adequate supply available, but there may be some delays in distribution. We think it is important that pharmacies, hospitals, and doctors work closely with their distributors, as they are in the best position to advise on these issues."
Dr. John Treanor, a professor of infectious disease at University of Rochester in New York, said Fluzone is by far the most widely used flu vaccine in the United States.
"But at this point obviously most people who are going to be vaccinated already have been, so the effects of a vaccine shortage would probably be minimal -- although frustrating for those people who do still want vaccine," he said.
Shortages of Tamiflu would be more problematic because this is the middle of the outbreak, Treanor said.
"General recommendations are that antiviral therapy should be targeted to those individuals with higher risk of influenza complications or with severe disease, and not used routinely in otherwise healthy individuals with uncomplicated flu," he said.
Dr. Marc Siegel, an associate professor of medicine at NYU Langone Medical Center in New York City, said 135 million doses of flu vaccine were manufactured and 128 million doses have been distributed. "The question is how many of the flu shots that were distributed actually got used," he said.
Siegel said Tamiflu is the most effective antiviral for flu, although there are alternatives. "Tamiflu significantly reduces symptoms, severity and length of contagion," he said.
Siegel is concerned, however, that people might panic and hoard Tamiflu. "We need calm... The flu should be declining by a month from now," he said.
For more information on flu, visit the U.S. Centers for Disease Control and Prevention.