Catching Measles Makes You More Susceptible to Other Diseases

(Inside Science) -- Scientists have discovered one more reason to vaccinate your children against measles: The highly contagious disease cripples the immune system’s “memory,” leaving people more susceptible to a host of other illnesses.

Since 1963, public health officials have had a powerful weapon against measles in the form of a vaccine, but in the past decade the virus has landed some significant counterpunches, hopping nimbly around the world and proliferating in communities with low vaccination rates. This year, the U.S. has recorded more than 1,250 cases of measles, the highest number in more than a quarter century, and the general trend extends around the globe .

Children who catch measles face potentially deadly complications such as pneumonia or brain swelling. Doctors have also noticed that even after individuals recover from visible symptoms, their immune systems can remain suppressed for an extended period of time.

Scientists now have new insights into how the virus can hobble the body’s natural defenses for years. In a paper published this week in the journal Science, researchers report that unvaccinated children from a Dutch Orthodox Protestant community who caught measles lost between 11% and 73% of the antibodies that the scientists had found in their blood before the disease. Antibodies are proteins that the immune system uses to identify and destroy invaders.

In a separate study, another group of scientists looking at blood samples from the same community found that some populations of immune cells called B memory clones, which help the body quickly attack pathogens it has encountered before, plummeted after measles infections. They also found that in two cases, the virus seemed to reset the immune system to an immature state less able to respond to new infections. That study will be published in the journal Science Immunology this week.

Both groups bolster their claims with animal studies and by looking at the blood of groups of people who did not get measles.

For scientists, the studies open new windows on the inner workings of the immune system. For the public, the findings reinforce a clear health message: To protect the lives and well-being of everyone, communities need to reach and maintain high rates of measles vaccination.