Health officials on Friday predicted a shortage in swine flu vaccine supplies, as the numbers of cases, hospitalizations and deaths grow to levels unprecedented for this time of year.
Flu caused by the H1N1 virus is widespread in 41 states, and flulike illnesses account for 6.1 percent of all doctor visits.
"That's high for any time, particularly for October," said Dr. Anne Schuchat, the director of the National Center for Immunization and Respiratory Diseases at the Centers for Disease Control and Prevention.
Forty-three children have died from swine flu since Aug. 30 — about the same number that usually die in an entire flu season. Nineteen of the 43 who died were teenagers, and 16 were ages 5 to 11 years old; the rest were under 5.
"These are very sobering statistics," Schuchat said in a news briefing, "and unfortunately they are likely to increase."
Fifteen percent to 20 percent of the patients who were hospitalized for the flu wound up in the intensive care unit, a rate comparable with that for seasonal flu. Although the disease continues to spread, its severity is not increasing.
Projections of the supply of swine flu vaccine have widely varied. During the summer, health officials said 120 million doses would be ready in October. They later dropped the estimate to 40 million doses by the end of the month.
Now, Schuchat said, they expect only 28 million to 30 million doses, adding that the exact numbers were impossible to predict and could change daily. She said vaccine manufacturers were reporting that production was behind schedule.
As of Wednesday, Schuchat said, 11.4 million doses of the H1N1 vaccine were available, with more being shipped. She predicted that by early November, there would be widespread vaccine availability and information on where people should go for it.