Measles can wipe out immune system memory, increase vulnerability to other infections

Measles, in and of itself a severe and sometimes deadly disease, can also cause lasting harm to the immune system and leave people vulnerable to other serious infections, such as flu or pneumonia, according to a new study.

The research, led by Harvard T.H. Chan School of Public Health’s Michael Mina, is the first to find that measles can cause what scientists call “immune amnesia.” Measles can wipe out the immune system’s memory of previous illnesses, making those who recover susceptible to infections they may have been protected from before contracting the virus.

Mina, assistant professor of epidemiology, conducted the study as a postdoctoral researcher in the lab of senior author Stephen Elledge at Harvard Medical School and Brigham and Women’s Hospital. Mina, Elledge, and colleagues looked at blood samples from 77 unvaccinated children in the Netherlands, taken both before and after a 2013 measles outbreak. The team found that, after getting measles, the children lost 11–73% of their infection-fighting antibodies. A group of 33 children who had been vaccinated didn’t lose antibodies.

The researchers also studied macaques infected with measles and found that, for at least five months, the monkeys lost 40-60% of their antibodies for pathogens they’d been exposed to in the past.

Mina said in an October 31, 2019 New York Times article that children who get measles can rebuild lost immunity, but only if they are re-exposed to infections or get vaccinated.

At a time when measles cases are increasing worldwide, the new findings highlight the importance of the measles vaccine, said Mina.

“When parents say no to getting a measles vaccine, you’re not just taking a risk of your kid getting measles, you’re causing them to lose this amazing resources of defenses they’ve built up over the years before measles, and that puts them at risk of catching other infections,” he said. “You’ve got to watch your kid’s back for a few more years.”

Read the Harvard Medical School press release: Inside Immune Amnesia

Read the New York Times article: Measles Can Cause “Immune Amnesia,” Increasing Risk of Other Infections

Read a Nature article: Measles erases immune ‘memory’ for other diseases