Early H1N1 infection may prevent worse strain*
Tursday Oct 15, 2009 (foodconsumer.org) -- A new study in the November print edition of the Journal, published by the Centers for Disease Control and Prevention, suggests that getting infected with certain flu may help protect against more virulent viruses in the future.
The study found the 2009 H1N1 flu virus, or swine flu, has some immunologically important sites that are also found in seasonal flu viruses that have been circulating for years.
Zheng Xing and Carol Cardona at the University of California, Davis, said more than a dozen structural sites, or epitopes, found in both swine flu virus and some seasonal flu may explain why many people older than 60 carry antibodies or cell-mediated immunity against the H1N1 virus.
"These findings indicate that human populations may have some level of existing immunity to the pandemic H1N1 influenza and may explain why the 2009 H1N1-related symptoms have been generally mild," Cardona said.
"Our hypothesis, based on the application of data collected by other researchers, suggests that cell-mediated immunity, as opposed to antibody-mediated immunity, may play a key role in lowering the disease-causing ability, or pathogenicity, of the 2009 H1N1 influenza," Xing added.
It has been observed that people who are exposed to a mild strain of flu virus may be less likely to get a more virulent strain of the same virus.
In 1915 and 1916, many Hispanics and Blacks got infected with a mild form of flu virus yet they seemed to be less susceptible to the more virulent flu virus that caused the famous 1918 Spanish flu pandemic which killed millions of people.
The U.S. government and the news media have been saying for many months that the H1N1 flu virus may mutate some day to become a form of more virulent and deadly flu virus that may cause some flu pandemic like the one that occurred in 1918.
The study seemed to suggest that becoming infected with the circulating H1N1 flu virus may help prevent such a virulent and potentially lethal H1N1 flu.
The currently circulating H1N1 virus is mild and H1N1 flu deaths are rare. H1N1 flu symptoms include fever, cough, sore throat, runny or stuffy nose, body aches, headache, chills and fatigue, according to the Centers for Disease Control and Prevention.
By david Liu - davidl at foodconsumer dot org and editing by Sheilah Downey - sheilahd at foodconsumer dot org