Flu viruses that circulated decades ago may be protecting older adults from the new swine flu virus, scientists at the U.S. Centers for Disease Control suggested Thursday.
Blood samples from U.S. children don't produce any antibodies when exposed to the new H1N1 virus, but antibodies were detected in about one third of the samples from older adults, the study shows. But whether those antibodies would block infection with the new virus can't be revealed by this kind of testing.
"We don't yet understand what that means in terms of protection, if anything at all," said Dr. Jacqueline Katz, first author and chief of the immunology and pathogenesis branch of the CDC's influenza division.
Others remarked, though, that the laboratory finding is intriguing because it mirrors what is being seen in the real world as the virus spreads.