Old seasonal flu antibodies target swine flu virus

Old seasonal flu antibodies target swine flu virus
Lab results could explain why young patients are hardest hit by current H1N1 strain.
Heidi Ledford Published online 21 May 2009 | Nature
Antibodies against some seasonal flu strains from prior years may be active against the new H1N1 swine flu currently circulating the globe, a recent study reports. The findings suggest an explanation for why swine flu appears to infect the young more often than the elderly, who are normally more susceptible to seasonal flu viruses.
Only 1% of swine flu cases in the United States are in people over the age of 65.CDC
The study, published today in the Morbidity and Mortality Weekly Report, analyzed blood samples taken from 359 participants in flu vaccine studies conducted from 2005 to 2009. 33% of the samples from people over 60 years old had antibodies that reacted with the swine flu virus, as compared to 6%-9% of the samples from people aged 18–64 years, and none of the samples taken from children 1.
The results match the apparent current epidemiology of swine flu infection, says Anne Schuchat, interim deputy director for the Science and Public Health Program at the Centers for Disease Control and Prevention (CDC) in Atlanta. Most cases of swine flu have occurred in people who are under 60 years old, and only 1% of confirmed swine flu infections in the United States were in patients over the age of 65.
Nevertheless, the results should be interpreted with caution, Schuchat urged in a press briefing today. Researchers have shown that the antibodies react with the virus in test-tube assays, but they have not yet shown that the antibodies can fend off the virus in animals or people. "Whether this particular assay will pan out over time as predictive of clinical protection, we can't say," Schuchat said.

Lab results could explain why young patients are hardest hit by current H1N1 strain.
Heidi Ledford Published online 21 May 2009 | Nature
Antibodies against some seasonal flu strains from prior years may be active against the new H1N1 swine flu currently circulating the globe, a recent study reports. The findings suggest an explanation for why swine flu appears to infect the young more often than the elderly, who are normally more susceptible to seasonal flu viruses.
Only 1% of swine flu cases in the United States are in people over the age of 65.CDC
The study, published today in the Morbidity and Mortality Weekly Report, analyzed blood samples taken from 359 participants in flu vaccine studies conducted from 2005 to 2009. 33% of the samples from people over 60 years old had antibodies that reacted with the swine flu virus, as compared to 6%-9% of the samples from people aged 18–64 years, and none of the samples taken from children 1.
The results match the apparent current epidemiology of swine flu infection, says Anne Schuchat, interim deputy director for the Science and Public Health Program at the Centers for Disease Control and Prevention (CDC) in Atlanta. Most cases of swine flu have occurred in people who are under 60 years old, and only 1% of confirmed swine flu infections in the United States were in patients over the age of 65.
Nevertheless, the results should be interpreted with caution, Schuchat urged in a press briefing today. Researchers have shown that the antibodies react with the virus in test-tube assays, but they have not yet shown that the antibodies can fend off the virus in animals or people. "Whether this particular assay will pan out over time as predictive of clinical protection, we can't say," Schuchat said.