Getting sick with measles does not just result in a dangerous infection that causes itchy blisters. It can leave the immune system vulnerable to other infections for some time to come, a new study has found.
Although there had been earlier hints of such "immune amnesia," this study is the first to show how the process might work. The researchers analyzed antibodies to essentially the entire repertoire of viruses that humans face, in drops of blood taken from 77 unvaccinated Dutch children just before and just after they came down with the measles. The children live in a part of the Netherlands where many families forgo vaccination for religious reasons, and the researchers took advantage of an ongoing measles outbreak there to gather samples. All the children recovered and their immune systems functioned normally—but after the infection they were missing many of the antibodies that were present before they fell ill, the study found.
"Measles is much worse and deleterious of a virus than we ever knew," says Stephen Elledge, the senior author on the paper published this week in Science. "Getting the measles virus is like being in [a car] accident—only what's damaged is your immune system," says Elledge, a professor of genetics and medicine at Harvard Medical School and a Howard Hughes Medical Institute investigator at Brigham and Women's Hospital in Boston.
This immune erasure means that the children have to fight off the same bacteria and viruses they had already conquered. In the U.S., where many children are generally healthy and have access to good health care, a quarter of measles patients end up in the hospital during their infection and deaths are rare, Elledge says. Aftereffects of the disease might lead to antibiotic prescriptions or rehospitalizations.
In the developing world, however, this measles-related immune amnesia probably leads to a lot of avoidable deaths, says Matthew Ferrari, an associate professor of biology at Pennsylvania State University, who was not involved in the research. "Without a doubt, measles is a disease of inequity," he says. "The vast burden of measles mortality is felt in the poorest and least accessible populations."
Click here to read the rest of the story on ScientificAmerican.com
Photo by EU Civil Protection and Humanitarian Aid Operation