If the advocates for immunization didn't have a strong enough case already, they can now add another arrow to their quiver. It turns out children who contract measles not only suffer a potential life threatening illness, but their immune system takes a whack for up to three years afterwards.
It was well established that measles crippled the immune system following infection, and that the memory cells that recognize pathogens, thereby jump starting the body's immune reaction, were debilitated for a short period. But in a new study published this week in the journal Science, researchers are now finding that the measles-induced "immune amnesia" isn't quite so short lived.
"We already knew that measles attacks immune memory, and that it was immunosuppressive for a short amount of time. But this paper suggests that immune suppression lasts much longer than previously suspected," co-author of the study and assistant professor at Princeton University, Jessica Metcalf says.
The memory cells are part of the adaptive immune system each of us acquires throughout our lifetime. We are constantly exposed to pathogens in our environment, and it's the job of the adaptive system to create a memory file of such threats. That way, when we encounter them in the future, the body is armed and ready. The memory cells recognize the pathogen, alert the immune system to the pathogen's presence, and launch the assault team to destroy the invading organism.
But measles is a unique pathogen. For starters, it is highly contagious. This pesky virus replicates in the nose or throat of the infected person, so all it takes is a sneeze, a cough, or a simple conversation for the infected droplets to take flight. And once they leave the body, they can hang around on surfaces or remain suspended in the air for several hours. Simply touching an infected surface or breathing infected air allows the virus to gain entry.
And even if the child recovers from the infection, their immune system lags far behind.
According to Metcalf, "In other words, if you get measles, three years down the road, you could die from something that you would not die from had you not been infected with measles."
Metcalf and colleagues examined death record among European children between the ages of 1 and 9, and American children between 1 and 14, in both pre- and post-vaccine eras. What they discovered was a strong correlation between measles contraction and death from other diseases, usually within a 28 month window following infection.
And what role might vaccinations play in reducing the incidence of death from other pathogens following a measles infection? Lead author Michael Mina, a medical student at Emory University, summed it up.
"Our findings suggest that measles vaccines have benefits that extend beyond just protecting against measles itself."
Food for thought when it comes to vaccinating your child.