Measles Virus Destroys Immune System’s Memory of Past Infections

With the resurgence in measles epidemics worldwide, researchers conducted two studies to determine whether measles infection causes long-term damage to immune memory and found it can greatly diminish previously acquired immune memory, potentially leaving individuals at risk for infection by other pathogens. To identify and quantify long-term effects of measles on the immune system, the scientists used VirScan, an assay that tracks antibodies to thousands of pathogen epitopes in blood, to study 77 unvaccinated children before and two months after they became infected during a 2013 measles outbreak in the Netherlands. Results showed measles eliminated 11 percent to 73 percent of the antibody repertoire across individuals.

Before the children contracted measles, their blood contained antibodies to many common pathogens. “These were really healthy kids,” said Michael Mina, a Harvard virologist and one of the researchers in the study. After the disease, the children lost, on average, about 20 percent of their antibody repertoire. Some fared much worse, losing more than 70 percent of their immunity to viral pathogens. They did not see the effect in their controls: five unimmunized children who never contracted measles over the course of the study, as well as more than 100 other children and adults. They also saw no loss of antibodies in children after they received a vaccination against measles. The reduction in humoral immune memory after measles infection generates potential vulnerability to future infections, underscoring the need for widespread vaccination.