Measles Virus Infection Destroys Immune System Memory

Henrietta Brewer
November 8, 2019

The measles virus affects "cells" of the immune system, leaving patients at and sometimes even to several years after infection, much bevattelijker for use in other disease states.

Researchers knew that measles eliminates B cells in the immune system that form its memory.

The second study, which was published on October 31 in Science Immunology, takes an even more direct approach to investigating the havoc that measles infection wreaks on the immune system. They analyzed blood samples from a group of 26 children ages 4 to 17 who were unvaccinated and had never had measles-meaning they could develop the infection organically-both when they were healthy, and again after a measles outbreak in the community. The research revealed two months after recovering from a measles infection the children had lost between 11 and 73 percent of their immune antibody memory. So, while people who come down with measles are protected from future bouts of that virus, they seem to be left unprotected from other, previously known pathogens and ill-equipped to respond to new ones.

The measles vaccine does far more than keep one disease at bay.

Indeed, before the measles vaccine was presented during the 1960s, an expected half of youth deaths may have been related with infections that children got subsequent to enduring an episode of measles, as indicated by a recent report distributed in Science. A more specific experiment in ferrets revealed infection with the measles virus reduced protection from prior flu vaccination, again affirming the occurrence of immune amnesia following viral infection. "Our immune cells recover back to normal numbers [after getting measles]", Petrova says, "but they are no longer the same memory cells".

As well as solidifying the importance of administering measles vaccinations, the new research debunks the long-held myth than exposure to measles actually strengthens the immune system. This hypothesis has already been supported by previous studies, including evidence that associates measles with up to 50% of childhood deaths from infectious diseases.

The notorious measles infection not just makes individuals debilitated, it likewise sneaks inside significant safe cells in the body and wipes their "memories", new research recommends. 'By preventing damage to your immune system, you do not have an increased risk of picking up other infectious diseases'.

Each time you get a cold or an infection, your body forms antibodies to fight these bugs.

Study co-author Rik de Swart had gathered blood samples from unvaccinated children during a 2013 measles outbreak in the Netherlands.

For years there have been questions about why measles vaccinations decreased childhood deaths overall, with some people arguing that the vaccine might actually be boosting existing immunity to other pathogens, even though it is created to protect only against measles.

"Imagine that your immunity against pathogens is like carrying around a book of photographs of criminals, and someone punched a bunch of holes in it", said the study's first author, Michael Mina, a postdoctoral researcher in the laboratory of Stephen Elledge at Harvard Medical School and Brigham and Women's Hospital at the time of the study, now an assistant professor of epidemiology at the Harvard T.H. Chan School of Public Health.

One of the most contagious diseases known to humankind, measles killed an average of 2.6 million people each year before a vaccine was developed, according to the World Health Organization. "Measles is not as harmless of a disease as many people think".

The European work, led by Velislava Petrova of the Wellcome Sanger Institute at Cambridge University, looked at the effect of the measles on B cells, which generate antibodies.

Prof. William Moss, a global vaccine expert at the Johns Hopkins Bloomberg School of Public Health who was not involved with the paper, says it is the most sweeping study yet of the impact that measles has on the antibodies that protect us from diseases.

"What this has done is document exactly how that immunosuppression takes place, and gives us a sense of how broad that immunosuppression can be", said Dr. William Schaffner, an educator of preventive medication and irresistible ailment at Vanderbilt University who was not associated with the work. Antibody depletion was not observed in infants vaccinated against measles, mumps and rubella.

Three years exposed to any infection, even the slightest leave a huge mark on the body, and even jeopardize its functioning.

Examining the diversity of the antibody repertoire, the team found that measles infections were linked with a reduction of about 20% in the overall diversity of the antibody repertoire as measured by VirScan.

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