Measles Leaves Lasting Impact on the Immune System

Measles may impact one’s immune system longer than previously thought.

New research published in Science posits the immune system’s vulnerability after measles infection can last up to 2 to 3 years, meaning patients could die from a subsequent infection they might not have been as susceptible to if they had avoided the virus altogether.

Data from high-income countries showed a correlation between non-measles infectious disease mortality and measles incidence for about 28 months on average after the measles infection. The population the researchers examined included American children aged 1 to 14 years, both before vaccination became commonplace and after.

The results of the study place greater emphasis on the importance of the measles vaccine—not only for measles, but also for avoiding infectious diseases that can follow measles infection.

The researchers said measles’ effect on the immune system causes a type of memory loss, where cells forget how to protect the body from viruses.

“By preventing measles-associated immune memory loss, vaccination protects polymicrobial herd immunity,” the researchers added.

Despite the measles vaccine’s ability to boost herd immunity, not enough people are getting vaccinated, so the herd may be “too thin to be effective,” Jason Gallagher, PharmD, FCCP, a clinical pharmacy specialist in infectious diseases at Temple University, told Pharmacy Times during a measles outbreak earlier this year.

Dr. Gallagher said the outbreak at Disneyland in California showed the impact of locally high rates of unprotected children, and he also underscored the high transmission rate of the virus.

“It is extremely contagious to an extent that few infectious disease are,” Dr. Gallagher said. “Every person infected will spread [the virus] to about 90% of non-immunized contacts.”

The researchers of the measles study also explained why the virus is especially hazardous. They said their findings were consistent with previous studies suggesting the measles virus attacks B and T lymphocytes, which help the body fight off infection.

“Our findings suggest that measles vaccines have benefits that extend beyond just protecting against measles itself,” said lead author Michael Mina, a medical student at Emory University who worked on the study as a postdoctoral researcher at Princeton, in a press release. “It is one of the most cost-effective interventions for global health.”

According to the US Centers for Disease Control and Prevention, there have been 169 cases of measles across 20 states and the District of Columbia between January 1 and May 1, 2015. The majority of these cases stemmed from the Disneyland outbreak.