Measles infections can give the immune system amnesia

The immune system detects the presence of invading microbes that it recognizes from earlier infections, and initiates a full-blown immune response. New research is showing that the measles virus can significantly alter this previously acquired immune memory, with potentially life-threatening consequences.

A study published in Science showed that children who succumbed to measles infections showed signs of substantial immune suppression for as long as three years after symptoms disappeared. As a result of this “immune amnesia”, patients became susceptible to severe viral or bacterial illnesses, even from pathogens they had already encountered before.

For vulnerable babies and young children, this is a matter of life and death. Research showed that immune protection against viruses diminished up to 70 percent in the months and years following a measles attack. This was a result of the depletion of specific antibodies that “remember” past invaders. Indeed, many measles-related deaths are a result of secondary infections while defense barriers are low.

Measles is a highly contagious infectious disease that can be particularly dangerous for children under the age of five, causing permanent disabilities or even death. The World Health Organization made lofty predictions a decade ago, forecasting the imminent eradication of the measles virus worldwide. However, statistics from 2018 indicate that the measles virus isn’t going anywhere, with over 140,000 deaths prompting widespread concern and a resurgence in global vaccination efforts.

The measles vaccine has been found to be safe and protects against the disease effectively. Furthermore, the researchers demonstrated the importance of the vaccine in preventing measles’ post-infection immunosuppressive phase. 

Advocating for measles vaccinations for all, Gregor Mendel Professor of Genetics and of Medicine, Stephen Elledge said, “We now understand the mechanism is a prolonged danger due to erasure of the immune memory, demonstrating that the measles vaccine is of even greater benefit than we knew.”

Sources: Science, Harvard Medical School.