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Video: Measles Causes "immune Amnesia" And Weakens Defenses Against Other Infections
Measles causes "immune amnesia" and weakens defenses against other infections
Scientists have shown that measles, a potentially fatal and highly contagious disease, is even more dangerous than most people think. It is able to induce "immune amnesia" by removing antibodies that protect against other diseases.
Photo: CDC Global /
In two separate studies of religiously unvaccinated children from the Orthodox Protestant community in the Netherlands, measles significantly erases the immune system's memory of previous illnesses, returning it to an immature state. As a result, the body is less prepared to fight new infections.
This means that measles can weaken the protection provided by vaccines against other infections - influenza, tuberculosis, diphtheria. Thus, outbreaks of measles can trigger outbreaks of other diseases. The findings make the need for measles vaccination even more urgent.
Scientists at Harvard Medical School took blood samples from 77 unvaccinated children and tested their immune systems before and about two months after they contracted measles during the 2013 outbreak. The researchers found that the virus destroyed 11 to 73% of the patients' protective antibodies, putting them at greater risk of viral and bacterial strains to which they were previously immune. The results are published in Science.
“Imagine that your immunity against pathogens is like carrying a book of photographs of criminals and someone has punched a lot of holes in it. Then it would be much more difficult to recognize this criminal if you saw him, especially when holes are punched in such important elements for recognition as the eyes or mouth,”said Michael Mina, one of the main authors of the study.
The researchers also tested children vaccinated against measles and found no drop in antibody levels.
In a study by a team at Cambridge University and published in Science Immunology, B cells of the immune system, which are involved in the production of antibodies, were studied using genetic sequencing. Scientists tested samples from 26 unvaccinated children and found that memory cells formed to fight certain diseases had disappeared. Another type of B-cell (naive) was also depleted, leaving the immune system in an "immature state."
“This is… a direct human demonstration of 'immune amnesia', when the immune system forgets how to respond to previously encountered infections,” said Velislava Petrova, who led the study.
The fact that measles suppresses the immune system was first noticed by researchers over 100 years ago. Austrian scientist Clemens von Pirke discovered in 1908 that a child who tested positive for tuberculosis had a negative result after contracting measles.
Michael Meena, in a 2015 paper in Science looking at disease patterns in several countries since measles epidemics before vaccine development, found that morbidity and mortality from other infectious diseases increased in the five years following the outbreaks. This study found that the measles virus may have been associated with 50% of childhood deaths from infectious diseases other than measles itself.
“These elegant studies provide insight into the post-measles immunological deficit that has intrigued scientists for over 100 years. I agree that the findings also strengthen the case for vaccination. But I do not think that this will change the level of vaccination, since such decisions are not rational,”said Ian W. Lipkin, an infectious disease specialist and immunologist.