Swine flu may have infected at least 63 million people in the U.S. last year, according to a study in Pittsburgh, where almost every second schoolchild probably caught the pandemic virus.
Blood tests on Pittsburgh residents found 45 percent of people aged 10 to 19 years had antibodies against the new H1N1 flu strain. About 22 percent of people across all groups developed immunity to the virus by early December and quarter of those born in the 1920s may have already had protective antibodies before the pandemic resulting from prior flu infection, researchers at the University of Pittsburgh found.
The findings, reported online yesterday in the Public Library of Science, suggest a fresh wave of swine flu infections isn’t likely unless the virus mutates or people become more susceptible to infection. A World Health Organization advisory panel is holding a teleconference tomorrow to discuss whether the first influenza pandemic in 41 years has peaked.
Blood tests on Pittsburgh residents found 45 percent of people aged 10 to 19 years had antibodies against the new H1N1 flu strain. About 22 percent of people across all groups developed immunity to the virus by early December and quarter of those born in the 1920s may have already had protective antibodies before the pandemic resulting from prior flu infection, researchers at the University of Pittsburgh found.
The findings, reported online yesterday in the Public Library of Science, suggest a fresh wave of swine flu infections isn’t likely unless the virus mutates or people become more susceptible to infection. A World Health Organization advisory panel is holding a teleconference tomorrow to discuss whether the first influenza pandemic in 41 years has peaked.
