Frustrated vaccine-seekers looking to prevent swine flu may also have driven up demand for protection against seasonal influenza to what could be record levels, government health officials said Tuesday.
Nearly 90 million doses of vaccine for seasonal influenza already have been distributed, out of a total of 114 million available doses. In a flu season that typically stretches to May, that means that the nation may run out of seasonal vaccine well before demand ceases.
"This year looks like it will be the highest-ever uptake of seasonal vaccine," Dr. Tom Frieden, the director of the Centers for Disease Control and Prevention told reporters. "It may be that there's greater demand than that before the end of the season."
In a typical year, about 100 million people in the United States get flu shots and a fair amount of leftover vaccine must be destroyed at the end of the season.
So far this year, however, there's little sign of seasonal flu in the U.S., where nearly all of the circulating flu virus is H1N1, or swine flu, Frieden said.
Supply of vaccine available to ward off that widespread infection is increasing, with 31.8 million doses now available, Frieden said.
That's far short of the 120 million doses previously expected to be available by about this time, but it's on track to be an increase of 10 million doses in a single week, he said.
Across the country, planned flu clinics have been shuttered and frustrated vaccine seekers have been turned away because of the delay in supplies.
"We know that it's not nearly as much as we would have liked," Frieden said. "We ask people to continue to be persistent."
People who have been thinking about getting a seasonal flu shot ought to act now, said Dr. William Schaffner, an infectious disease expert at Vanderbilt University in Nashville.
"It's going into noses and arms as we speak," he said. "Last year we threw away 27 million doses. This year, it's going to be all used up."