WASHINGTON - Influenza is circulating unusually early this year with cases in all 50 states - nearly all the swine flu variety, government health officials said Friday.
The highest concentration of flu cases is in the Southeast and a few other states, Dr. Anne Schuchat of the Centers for Disease Control and Prevention said at a briefing.
The good news is that testing of vaccines for swine flu show that they work with a single dose and take effect rapidly.
Supplies of swine flu vaccine are expected to be available in mid October, but the seasonal flu vaccine is available now, and officials have encouraged people to get it.
The H1N1 swine flu broke out in the spring and never went away, Schuchat said. It struck in many summer camps, spread into the Southern Hemisphere and now is widening its range. Currently, 98 percent of the flu viruses circulating are swine flu.
Cases are mainly occurring in children and young adults, Schuchat said.
The finding that the swine flu vaccine works in a single dose in healthy adults "shortens the window of worry," Health and Human Services Secretary Kathleen Sebelius said. "There's no better protection against the flu than vaccine."
While the single dose works in adults, testing is still under way to determine the effectiveness of the vaccine in children and pregnant women, said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Disease.
The CDC said influenza was widespread last week in Florida, Alaska, Arizona, Georgia, Louisiana, Maryland, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee and Guam.