Antibodies still protect 1918 flu survivors

Study demonstrates the durability of the human immune system

updated 1:36 p.m. ET, Sun., Aug. 17, 2008
WASHINGTON - Nearly a century after history's most lethal flu faded away, survivors' bloodstreams still carry super-potent protection against the 1918 virus, demonstrating the remarkable durability of the human immune system.

Scientists tested the blood of 32 people aged 92 to 102 who were exposed to the 1918 pandemic flu and found antibodies that still roam the body looking to strangle the old flu strain. Researchers manipulated those antibodies into a vaccine and found that it kept alive all the mice they had injected with the killer flu, according to a study published online Sunday in the journal Nature.

There's no pressing need for a 1918 flu vaccine because the virus has long since mutated out of its deadly form and is extremely unlikely to be a threat anymore, experts said. What's more important in this research, they said, is that it confirms theories that our immune system has a steel-trap memory.

"It's incredible. The Lord has blessed us with antibodies our whole lifetime," said study co-author Dr. Eric Altschuler at the University of Medicine and Dentistry in New Jersey. "What doesn't kill you, makes you stronger."

This is the longest that specific disease-fighting cells have lasted in people, said study lead author Dr. James Crowe, a professor of microbiology and immunology at Vanderbilt University Medical Center in Nashville, Tenn.

But these antibodies don't just survive; they have mutated tremendously and now bind tighter to disease cells than other antibodies. That makes them more potent, he said.

Crowe said he hopes to use similar techniques to boost the potencies of vaccines that would be more useful now against newer bird flu strains that could become epidemics.