The ever-changing flu virus is slippery, mutating so rapidly that vaccines designed to protect against it shield for a single season, if that long.
But what if a flu shot could be a one-time proposition, maybe a rite of childhood like so many other vaccines? In a year like this with pandemic influenza racing across the globe, officials have been left scrambling to develop a vaccine to guard against this new H1N1 virus, all the while preparing for the complicated annual ritual of giving seasonal flu shots to millions. Fearing such a pandemic, researchers for years have been working to create what is known as a universal flu vaccine, a single inoculation that would defend against severe infection from any type of flu - seasonal or otherwise.
So far, while there has been some progress, no one has succeeded. At least not in humans.
"We cannot protect against pandemics. We cannot make vaccine fast enough" when a new strain appears, said Dr. Hildegund C.J. Ertl, who heads the vaccine center at the Wistar Institute in Philadelphia. "If you have a universal vaccine, you stop worrying about pandemics. A lot of people are trying."
For several reasons, it could be a decade before a vaccine like this hits the market. Researchers still haven't determined whether the approach will work. Meanwhile, any vaccine would need to be championed by a manufacturer, and it could be difficult to find a company willing to take a risk when the vaccines currently on the market do a decent job most of the time.
"We're still pretty far away from any sort of [universal] vaccine," said Dr. Wilbur Chen, a vaccinologist at the University of Maryland's Center for Vaccine Development, where an experimental swine flu shot is being tested now. "We still haven't been able to find the right candidate."
Still, Chen said, developing one would answer many of the limitations of seasonal shots, which must be given again and again: "It would be great if it was like other vaccines where you could give one vaccine or a booster shot every so often and not have to do it every year. ... It's the panacea for what we're doing right now."
While researchers are attacking the universal flu vaccine problem from many directions, the goal is the same: to find a part of this ever-changing virus that doesn't change and take aim at that.
