08 November, 2019
Measles may be even more dangerous than doctors had thought. Researchers reported last week that the disease destroys immunity that the victim has developed to fight off other infections.
The researchers' findings help to explain why children often catch other infectious diseases after having measles. The findings also show the dangers of growing resistance to childhood vaccination in some countries.
Two studies have similar results
Two recent studies showed for the first time how measles resets the body's natural defenses against disease.
Velislava Petrova is with Cambridge University in England and the Wellcome Sanger Institute, a not-for-profit research center. She also was a co-leader of one of the measles studies.
"This ... is a direct demonstration in humans of ‘immunological amnesia', where the immune system forgets how to respond to infections encountered before," she said.
Geneticist and researcher Stephen Elledge was a co-leader of the second study. He said the results showed "really strong evidence that the measles virus is actually destroying the immune system."
Elledge is with the Howard Hughes Medical Institute in the United States.
The findings are important for public health efforts worldwide. A decrease in vaccination rates is leading to measles outbreaks in some areas. The spread of measles can lead to a return of other dangerous diseases, such as influenza, diphtheria and tuberculosis.
Importance of vaccines
Two injections of a vaccine can prevent measles. The treatment is safe and effective, and has been in use since the 1960s.
But World Health Organization, or WHO, experts warned last month of an "alarming upsurge" of cases among unvaccinated people all over the world.
In the first three months of this year, the number of cases jumped 300 percent from the same period in 2018, WHO reports show.
"The (measles) virus is much more deleterious than we realized, which means the vaccine is that much more valuable," noted Elledge.
For this research, the two teams studied a group of unvaccinated people in the Netherlands to find out what measles does to the immune system.
In one study, researchers examined antibody genes from 26 children. Then they compared the genes to another sample taken 40 to 50 days after measles infected the children. The researchers found that specific antibodies that had been built up against other diseases had disappeared from the children's blood.
Results from the second study found that measles infection destroyed between 11% and 73% of the children's protective antibodies. These antibodies are blood proteins that "remember" past contacts with viruses and help the body avoid repeat infections.
I'm John Russell.
Kate Kelland reported on this story for the Reuters news agency. John Russell adapted it for VOA Learning English. George Grow was the editor.
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Words in This Story
immunity – n. the ability of a person or creature to resist an infection by the action of antibodies or white blood cells
amnesia - n. a condition in which a person is unable to remember things because of brain injury, shock, or disease
encounter – v. to come into contact with or face something
outbreak – n. the sudden violent start of something
upsurge – n. a sudden increase or rise — usually + in or of
deleterious - adj. damaging or harmful
specific – adj. clearly defined
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