New details on immune system ‘amnesia’ show how measles causes long-term damage

Measles wages war on cells of the immune system. Now two tallies of the carnage, described in the Nov. 1 Science and Science Immunology, offer even more compelling support for the measles vaccine.

The measles virus infects immune cells and erases their memories of earlier threats, raising the risk of contracting other infections for up to three years (SN: 5/21/19). Researchers including geneticist Stephen Elledge, a Howard Hughes Medical Institute investigator at Brigham and Women’s Hospital in Boston, put numbers to this erasure with a tool called VirScan. It measures antibodies, proteins made by immune cells that recognize previously encountered infections, in blood.

With VirScan, the researchers searched human blood for antibodies, each of which recognized one of about 400 infectious viruses, as well as some bacteria. Blood tested from 77 unvaccinated Dutch children, taken before and about seven weeks after a bout of measles, showed that the children’s immune systems suffered after the disease. Kids lost from 11 to 73 percent of their antibodies for specific threats, including viruses that cause common colds and a type of severe respiratory illness in young children, the team reports in Science.

Measles infections also interfere with the body’s ability to replenish a type of memory-storing immune cell called B lymphocytes, scientists report in Science Immunology.

Together, the results show how measles is a particularly damaging virus, and attest to the “immense public health value of the measles vaccine,” the researchers write in Science.