This year's flu season is looking a little dire. Thirteen children have already died, according to the most recent data provided by the Centers for Disease Control and Prevention, and almost every state has reported widespread flu activity.
If you haven’t gotten your flu shot, experts say you should go get it—right now—even though some have estimated the flu vaccine may only be 10 percent effective against this year’s most common strains.
We could be doing better than 10 percent. We could, for example, be using a universal flu vaccine.
Flu vaccines work because they can train our immune systems to be ready for a real attack by showing them a way to recognize the influenza virus. For influenza A, vaccines use parts of humagglutinin proteins, which look a little like a stalk of broccoli, National Institute of Allergy and Infectious Diseases director Dr. Anthony Fauci told Newsweek. (Fauci and his colleagues recently wrote a paper explaining the importance of a universal flu vaccine for the New England Journal of Medicine.)
Like broccoli, there’s a big poofy bit on hemagglutinin proteins. This broccoli-like head is currently the part used to make vaccines. “But it’s also the part that changes,” Fauci said—and it can change quite a bit.
That means every year, scientists must make an educated guess about what virus is likely to be the one that makes people sick. This approach has obvious downsides, Fauci noted. “We’re constantly trying to play a catch-up game.”
In theory, a universal flu vaccine would be one shot to protect against all influenza A strains by using a part that doesn’t change as much from year to year—like the stalk.
However, just chopping off the head won’t work. The stalk might not be stable without it, which means the immune system wouldn’t respond to it as well. In most cases, keeping the head on won’t work either. “The head is what we call immunodominant,” Fauci said; that means the immune system will respond more to the head and not to the stalk, defeating the point of a universal vaccine.
To solve this problem, scientists at the NIH and outside of the agency are following Dr. Frankenstein’s example—creating a new thing with relevant bits and pieces. One possible option is to stick a head that doesn’t provoke as much of an immune response on a stalk that does, encouraging the body to recognize the stalk; another would be to stick stalks on nanoparticles, a strategy Fauci said NIH scientists are currently testing.
Figuring out how to give the immune system something to react to is one part of the problem, Fauci noted. Provoking a reaction that’s strong enough for a vaccine to be effective is another—even for a universal one. “At its best, even with a good match, influenza vaccines are like 60 percent effective,” he said.
Though we could be doing better, Fauci and his colleagues noted in their paper it’s better not to wait for a universal flu vaccine. Get the one we’ve got now instead.
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