Seasonal Flu Vaccine May Cut Swine Flu Risk
Researchers Say Seasonal Flu Provides Some Cross-Immunity Against H1N1 Swine Flu
Because H1N1 viruses did not circulate from 1958 through 1978, it's possible that people born around that time had less chance to be primed by H1N1 infection during childhood, when people are most likely to catch the flu. The years don't exactly match, but Sanchez finds the coincidence quite interesting.
"So now, 30 years later, you are 32, 35, and get the seasonal vaccine and whoa! It didn't protect you against the H1N1 swine flu, because you were not primed by an H1N1-like strain," he suggests.
What all this means, Sanchez says, is that getting the flu vaccine every year offers extra benefits.
"The more vaccination or natural infection you get that allows your immune system to be primed against different kinds of flu viruses, the better off you will be," he says. "So this speaks for getting your seasonal flu vaccine. If there's one message I want to get out, this is it."
Even so, it would be a bad idea to count on the seasonal flu vaccine to protect you against H1N1 swine flu. The new vaccine raises antibodies that can protect you from infection -- which would be a much better thing than getting even a "mild" case of flu. And if you're also primed with a prior flu shot, so much the better.
The researchers compared 1,205 lab-confirmed cases of 2009 H1N1 flu in people of all branches of military service people to 4,810 service people without flu.
Sanchez presented the findings at the annual meeting of the American Society of Tropical Medicine and Hygiene, held Nov. 18-22 in Washington, D.C.