Measles Causes Immune Amnesia

Measles cases in the United States have surpassed the highest number on record since the disease was declared eliminated nationwide in 2000. Besides the signature splotchy red rash, fever, and watery red eyes; measles causes transient immune suppression, leading to increased susceptibility to opportunistic infections.

Previously, scientists determined that in non-human primates, measles virus depleted pre-existing memory lymphocytes. A measles outbreak in the Dutch Orthodox Protestant community in the Netherlands gave scientists the opportunity to study the pathogenesis of measles immune suppression in unvaccinated children. Parents part of the community there refuse vaccinations, a decision that ushers in regular bouts of measles. The community’s last measles outbreak ended in 2000; it was just a matter of time before the virus took hold again. The researchers got permission from parents to take blood samples from healthy, unvaccinated children to study their immune cells. Then, the researchers waited for an outbreak, so they could test the kids again after an infection. The data found that measles patients had similar levels of memory T and B cells as observed in non-human primates, supporting the immune amnesia hypothesis and offering an explanation for the previously observed long-term effects of measles on host resistance.

The immune system might take months, or even years, to bounce back from this memory loss. Researchers compared health records of U.K. children from 1990 to 2014. For up to five years after their bout of measles, children who had previously had the virus experienced more diagnosed infections than children who hadn’t. Children who'd had measles were 15 to 24 percent more likely to receive a prescription for infection than children who never had measles, the researchers reported. The study emphasized the importance of maintaining high measles vaccination coverage.

Laksono, B. M., de Vries, R. D., Verburgh, R. J., Visser, E. G., de Jong, A., Fraaij, P. L., ... & van Zelm, M. C. (2018). Studies into the mechanism of measles-associated immune suppression during a measles outbreak in the Netherlands. Nature Communications, 9(1), 4944.