Elderly may have greater swine flu immunity: U.S.

(ChinaPost.com.tw) – Older people may have some kind of immunity to swine flu, US health officials said Thursday, as the number of confirmed and suspected cases of H1N1 virus rose again around the country.

A study by the US Centers for Disease Control and Prevention (CDC) found that more than 64 percent of US infections have occurred among patients between the ages of five and 24, with just one percent of flu victims aged 65 or older.

One possible explanation is that “older adults might have been in contact a long time ago with a virus related to the one that we see now,” said Anne Schuchat, interim deputy director for science and public health programs at the US Centers for Disease Control and Prevention.

“Adults might have some degree of pre-existing … antibodies to the H1N1 virus, especially older adults over 60 or 65,” she added.

“The presence of pre-existing antibodies may be due to previous exposure to (influenza) infection or vaccination.”

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