News
Older adults seem to have some immunity to swine flu
Wall Street Journal
Older adults may have some immunity to the new H1N1 flu virus, the US Centers for Disease Control and Prevention said this week, a finding that could explain why the disease has spread mostly among children and young adults.
People who had been infected with a related H1N1 virus that circulated between 1918 and 1957 could have some protection against the new swine flu, said Daniel Jernigan, deputy director of the CDC’s influenza division.
The latest finding would confirm what many flu experts already suspect. US cases are mostly people between 5 and 24 years old; the majority of patients hospitalized are under 50 years old.
That’s quite different from the impact of a normal flu season, which takes its heaviest toll on the very young and the very old.
“It makes a lot of sense,” Richard Wenzel, chairman of the department of internal medicine at Virginia Commonwealth University, said of the finding. While visiting hospitals in Mexico City this month, “I saw young adults on respirators and young adults dying,” he said. “Older adults weren’t really part of the pattern.”
Only 13% of U.S. patients hospitalized with the new flu are age 50 or over, according to an analysis of a portion of those patients, Dr. Jernigan said. By contrast, 37% of patients are between the ages of 19 and 49 years old, 18% are between 10 and 18 years old, and 11% are between 5 and 9 years old.
