(MEDIA GENERAL) – For decades, the measles vaccine stumped scientists. They understood why it prevented the measles, but they couldn’t figure out why it also appeared to reduce cases of other infectious diseases.
But now, medical researchers believe they have their answer.
A new study led by Michael Mina, a medical student at Emory University, was published Thursday in the journal “Science.” Mina’s study focuses on the way the measles virus attacks a person’s immune system.
Most viruses are effective because they suppress a person’s immune system, but according to Mina, the measles virus takes that to a whole new level. Scientists believe the measles virus causes what they refer to as “immune amnesia” – the virus not only suppresses the immune system, but the immune system forgets how to protect the body against diseases it already has seen before.
“The immune system kind of comes back,” Mina told NPR. “The only problem is that it has forgotten what it once knew.”
According to the study, it can take up to a few years for a person’s immune system to fully recover from a measles infection.
Mina said his team first found the pattern while analyzing data from several countries dating back to the 1940s. The data showed that the number of measles cases predicted the number of deaths from other infectious diseases in the following two to three years.
Epidemiologist William Moss, who has studied the measles vaccine for more than 10 years with Johns Hopkins University, told NPR that while immune amnesia still is a hypothesis, Mina’s study shows “compelling evidence” of the measles’ long-lasting effects.
With the vaccine cutting down the measles, people’s immune systems stayed stronger to fight against other infectious diseases.
“Hence the reduction in overall child mortality that follows measles vaccination is much greater than previously believed,” Moss said.
Moss, who was not affiliated with the project, hopes the study will provide more motivation for parents to vaccinate their children.
“I think this paper will provide additional evidence – if it’s needed – of the public health benefits of the measles vaccine,” Moss told NPR. “That’s an important message in the U.S. right now and in countries continuing to see measles outbreaks.”