How Does Measles Reset Your Immune System?

Scientists have long known that when measles attacks your body, it goes to war against your white blood cells. Specifically, it binds to your B- and T-cells, then wipes them out. B- and T-cells are highly specialized cells critical to your health. They're the ones that recognize infectious germs in your body, then quickly multiply to fight off these unwelcome invaders. A subset of your B- and T-cells also remembers each infection you contract, thus providing you immunity should the infection strike again [sources: Science Museum, Smith-Strickland].

If measles trashes your white blood cells, you're at high risk of succumbing to a host of other infections. The medical community knew this, but thought patients were only vulnerable to other ailments for a few weeks post-measles. What intrigued health officials was the fact that after mass vaccinations occurred in the 1960s, childhood deaths from measles plunged as expected, but so did childhood deaths from a host of other infectious diseases. In resource-poor countries, the drop in childhood death rates post-measles-vaccination was as much as 30 to 50 percent. In some of the poorest nations, it was a whopping 90 percent [source: U.S. National Library of Medicine]. Why was this?

In 2012, researchers finally began to suspect why. A study with macaque monkeys showed that while the monkeys' immune systems began producing new B- and T-cells a month after contracting the measles, these new cells only remembered that the monkeys had had measles in the past. They didn't recall any of the other infections the monkeys had had. Basically, the monkeys' immune systems had amnesia. This meant the primates would have to suffer from all sorts of illnesses again to regain the immunity levels they'd built up since birth [source: Smith-Strickland]. Could the same be true for humans?

It appears so. In 2015, results of a study were published in the journal Science that showed childrenwho got the measles and survived were more likely to subsequently die from another infectious disease than kids who never got the measles. In the four countries studied — Denmark, England, Wales and the U.S. — the children's immune systems all appeared to be weakened for two to three years post-measles. Much like the monkeys, then, contracting measles trashes your immune system for several years after your recovery, making you susceptible to a host of other infections, and even premature death. (The researchers did say that due to the design of the study they could only find a link between measles infection and an increased risk of contracting other infectious diseases, but they couldn't prove a cause-and-effect relationship) [source: U.S. National Library of Medicine].

Although the measles vaccine is highly effective, measles remains one of the leading causes of death among young children globally. Nearly 110,000 people died from measles around the world in 2017, mostly children under the age of five [source: WHO]. On a positive note, because increasing numbers of kids are receiving the measles vaccination, deaths from this infectious disease plunged an incredible 80 percent between 2000 and 2017, which equates to the prevention of about 21.1 million deaths [source: WHO].

Measles is still common in impoverished countries, especially those in Africa and Asia, where vaccination levels are lower. Furthermore, outbreaks are especially damaging in countries recovering from a natural disaster or undergoing a conflict such as war. In these situations, the administration of vaccines is often interrupted, so more people are at risk of contracting the disease.

And when many people end up in cramped quarters, such as refugee camps or emergency shelters, the situation is ripe for an outbreak since measles spreads so easily. Transmitted mainly through coughing, sneezing and close personal contact, the virus can survive for up to two hours in the air and on surfaces. This means an infected person can cough in one room, then leave, and a second person walking into that room two hours later can contract measles simply by breathing in the contaminated air [sources: WHO, Parker].

With a highly effective and reasonably priced vaccine available, the fight continues to eradicate measles from the earth. A plan crafted by the Measles & Rubella Initiative, a cooperative effort between the American Red Cross, Centers for Disease Control and Prevention, UNICEF, the United Nations Foundation and the World Health Organization (WHO), one of its initiatives was to reduce global measles deaths by at least 95 percent compared to 2000 levels by the end of 2015. By 2017, they'd reached an 80 percent reduction in deaths thanks to improved vaccine coverage. The group plans to eliminate both measles and rubella (a related virus also called German measles) in at least five of the six WHO regions by the end of 2020 [source: WHO].