"This is even more of an argument for the vaccine," Seigel contended. "If people are immune based on previous outbreaks, imagine how good we can do with vaccinating the country. It seems that immunity is playing a pretty big role in areas where it spread previously, and if we vaccinate people we will really ante up on that."
This phenomenon has been seen before in other pandemic flu, Siegel said. "That was true of the 1918 flu," he said. "Areas that got heavy-hit in the spring didn't get hit again in the fall," he said.
Although areas hit hardest in the spring are seeing less-than-expected cases of flu, other parts of the country, where the flu was not as extensive, are seeing severe outbreaks, particularly in the Southeast, according to the U.S. Centers for Disease Control and Prevention.
For example, in Georgia since September there have been 81 hospitalizations and eight deaths from H1N1, according to the Georgia Department of Community Health, compared with 44 hospitalizations and one death from April through late July.
In Arkansas, seven pregnant women were in hospitals on respirators, the Times reported.
In addition, about half the children seen in the emergency room at Arkansas Children's Hospital in Little Rock have flu-like symptoms, which is almost double the usual number for this time of year Craig H. Gilliam, the hospital's director of infection control, told the Times.
For more information on H1N1 swine flu, visit the U.S. Centers for Disease Control and Prevention.
SOURCES: Marc Siegel, M.D., associate professor, medicine, New York University School of Medicine, New York City, and author, Swine Flu: The New Pandemic; Pascal J. Imperato, M.D., d
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