Medical sleuths have been trailing the elusive cold and flu viruses for more than a century. Now they finally might be onto something. A universal flu vaccine could be on the horizon -- and even more effective treatments for the common cold. Wayne Marasco, MD, PhD, is one of the most ardent sleuths. His perp -- the flu virus -- has caused the deaths of more than 36,000 Americans, and that’s just in one year.
Marasco is an associate professor of medicine at the Dana-Farber Cancer Institute and Harvard Medical School. His work means that a universal flu vaccine could be within reach -- one that would protect against all flu strains over a lifetime, just like existing vaccinations for diseases like measles and smallpox. Up to now, a universal flu vaccine has been elusive, because the virus's constant ability to change has made it a hard target to combat. "The virus undergoes a process we call antigenic drift, which means that it continuously evolves so that it escapes the immune system," he explains. "We've been kind of chasing our tails and immunizing every season to keep up with these variations."
According to the CDC, the flu vaccine reduces the odds of getting the flu by 70% to 90%.
You may wonder why there's such a wide range. And in fact, it's even wider than it seems: that statistic only applies to healthy adults. It turns out that the effectiveness of the flu vaccine depends on a number of different factors. Here's a rundown of what they are.
The flu vaccine doesn't work equally well in all people. It’s most effective in healthy adults. In young children, the flu vaccine...
Even though only two different types of flu virus -- A and B -- are responsible for most human flu cases, each type has several subtypes, and the virus can change from season to season. That's why researchers can never seem to keep up.
The 1918 Flu Pandemic
Compounding the problem is that people are always on the move. Hundreds of years ago, Europeans first carried the flu to North America on ships, infecting Native Americans who had previously been flu-free. Today, air travel can speed flu viruses (including the H1N1, or swine, flu) around the world even faster. Last year swine flu was reported for the very first time among the Matsigenka tribe deep in the Amazon jungle, proving that no place is too remote to escape a flu bug.
Even before the age of commercial air travel, the flu virus was able to get around. In 1918, after the influenza A virus jumped from birds to humans, soldiers in World War I spread the disease as they moved around the European front. By the time the worldwide pandemic had ended a year later, a quarter of Americans had become sick and 50 million people worldwide had died from the illness, which was named the Spanish flu.