LOS ANGELES – A new study suggests the measles shot comes with a bonus: By preventing that disease, the vaccine also may help your body fight off other illnesses for years.

It’s long been known that contracting measles weakens the immune system for weeks or months, putting people, especially children, at increased risk for potentially fatal infection by a host of germs.

Now, scientists find that this vulnerable period goes on much longer than thought, up to three years. So the benefit of avoiding measles also extends longer than was appreciated. Researchers also found that measles-vaccination campaigns were followed by a drop in deaths for other infectious diseases.

Experts said the work is a wake-up call to parents who don’t vaccinate their children out of unfounded fears about a link between vaccines and autism.

“The message is clear,” said Dr. Richard Wenzel, an infectious disease specialist at Virginia Commonwealth University who was not involved in the study. Not only is the vaccine safe and effective against measles, he said, but it also may save a child’s life by helping to guard against other infections.

Measles, marked by fever, cough and a blotchy rash, has been eliminated in the U.S. for more than a decade thanks to an aggressive vaccination effort. Outbreaks still crop up when Americans or foreign visitors become infected overseas and spread the virus among populations that are not vaccinated.

The study, released last week by the journal Science, was funded by the Bill and Melinda Gates Foundation and federal grants.