Older people who may have been exposed to the flu before 1957 appear to have some protection against the new H1N1 virus spreading worldwide, unlike younger people, a federal official said Wednesday.
Blood tests indicate that those people have antibodies capable of attacking the new virus, a finding consistent with evidence that the epidemic is hitting young adults hardest. Nearly 40% of patients are ages 19 to 49, says Daniel Jernigan, deputy director of the Centers for Disease Control and Prevention influenza division.
Older people may have stronger immune responses to the new H1N1 because, over time, they've been repeatedly exposed to H1N1 viruses, according to an analysis to be released today in a CDC bulletin called the Morbidity and Mortality Weekly report. The letters and numbers refer to the type of proteins on the viruses' surface.
The flu continues to spread across the USA; more than 5,700 cases have been reported in 47 states and Washington, D.C., Jernigan says. The death toll reached nine Wednesday when Utah recorded its first death, says Charla Haley of the Utah Department of Health. The 21-year-old man died in a Salt Lake City hospital.
So far, 247 people in the USA have been hospitalized. Nearly two-thirds have underlying conditions, including pregnancy, asthma and heart disease. A CDC report on 30 patients hospitalized in California found that most were admitted for pneumonia and dehydration. It also suggests that obesity may be a risk factor for more severe disease.
As of Wednesday, 36 schools had closed because of H1N1; 23 of the schools are in New York City, officials report. Globally, health officials report more than 10,000 cases and 80 deaths, most of them in the USA, Mexico and Canada.
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