According to two new studies, the measles virus not only makes you sick but also wipes out your immune system’s memory, affecting its ability to fight other infections.
Once you are infected by measles, your “amnesic” immune system fails to recognize harmful pathogens that it once used to fight, meaning you continue to remain vulnerable to deadly diseases, including the flu and pneumonia, in the future.
The studies were published in the journals Science and Science Immunology.
Study co-author and epidemiologist from Harvard University Dr. Michael Mina said, “Measles essentially takes away their ability to efficiently protect themselves.”
Researchers analyzed the data from a group of unvaccinated children in the Netherlands and suspected that the virus wipes out the immune system in a “profound” and lasting way.
Dr. William Schaffner from Vanderbilt University, who was not part of the studies, said, “What this has done is document exactly how that immunosuppression takes place and gives us a sense of how broad that immunosuppression can be,”
The results also draw the conclusion that this year’s measles outbreak in the United States will have “lingering” effects, explained Dr. Schaffner.
He said, “Those children are now living through a period of post-measles life more susceptible to other infections.”
The researchers have long hypothesized that the notorious measles virus may cause “immune amnesia,” but it was unclear how it did that.
They explained that once the virus invades the body, it wipes out a type of white blood cells called B-cell that fights the pathogens. Once the infection subsides, the white blood cell count goes back to normal levels; however, one may remain immunosuppressed for years.
The authors explained that measles survivors might recover from “immune amnesia,” but only by familiarizing themselves with all their previous pathogens. During the study period, some children regained new antibodies to ward off influenza, staph infections, and adenoviruses, which cause pharyngitis, sore throats, and pneumonia.
“What we were actually witnessing was reeducation of their immune system,” said Dr. Mina. “Getting bombarded by many infections at once could be particularly devastating.”
Dr. Duane Wesemann from Brigham and Women’s Hospital, who was not part of the studies, said, “One thing that is clear here is that the measles vaccine is a fantastic thing.”
The measles vaccine prepares the body with anti-measles antibodies, said Dr. Wesemann. “You get all of the good and none of the bad with the vaccine.” Referring to the recent measles outbreaks in the United States, Dr. Schaffner explained that studies like these highlight the importance of the measles vaccine to people. He said, “Measles should not be underestimated. It is clearly a disease worth preventing.”