Measles is far more dangerous than most people realise, new research shows.
The disease itself can cause a severe and sometimes deadly illness, but two new studies have found that even when patients recover, the virus can inflict lasting harm on their immune systems.
The weakened immunity leaves a child vulnerable for several years to other dangerous infections like flu and pneumonia. The damage occurs because the virus kills cells that make antibodies, which are crucial to fighting off infections.
Scientists call the effect “immune amnesia”.
During childhood, as colds, flu, stomach bugs and other illnesses come and go, the immune system forms something akin to a memory that it uses to attack those germs if they try to invade again.
The measles virus erases that memory, leaving the patient prone to catching the diseases all over again.
The findings make the need for measles vaccination even more urgent, because it protects children against much more than measles, the researchers said.
“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 resource of defences they’ve built up over the years before measles, and that puts them at risk of catching other infections,” said Dr Michael J Mina of the Harvard Medical School and Brigham and Women’s Hospital, the lead author of one of the new studies, published in the journal Science.
In fact if a person who has received vaccinations for other diseases contracts measles, it may wipe out the protection those vaccines had provided.
Revaccination could help restore the child’s immunity, the researchers said.
The second study, by a different team, was published in Science Immunology.
The studies arrive at a time of heightened concern about measles.
Globally, the measles vaccine is estimated to have saved 21 million lives between 2000 and 2017. But there are still more than 7 million cases and 100,000 deaths a year.
The New York Times
