A 1977 image of the mumps virus, which hit several Virginia colleges earlier this year. (Image via the Centers for Disease Control and Prevention)

It’s that time of year again, and Virginia’s college campuses are swarming with students who might gain a lot over the next semester: hopefully some knowledge, maybe a few pounds and possibly mumps.

So far, there have been 157 cases of mumps this year, more than three times the typical number the state sees. There were only 45 cases in 2017 and just 17 cases in 2016.

The culprit for the spike has been outbreaks on college campuses, according to Marshall Vogt, epidemiologist in the division of immunization with the Virginia Department of Health. In early 2018, there were several reported cases of mumps across Virginia’s colleges, including at James Madison University, the College of William and Mary and Virginia Commonwealth University.

Mumps is a vaccine-preventable disease, and though public health officials across the country have been grappling with the implications of the anti-vaccination movement, the vast majority of those infected with mumps on college campuses had received their recommended vaccinations.

“That was the kicker: At these schools, we had really high vaccination rates, but we were still seeing mumps being spread,” Vogt said.

Mumps is highly contagious and is usually known by the characteristic swollen cheeks and jaw that it causes. Symptoms include fever, headache and tiredness. Often those infected have mild or no symptoms, and they usually recover in a few weeks. However, it can have rare, but serious, complications, including deafness.

There are two likely causes of the outbreaks Virginia has seen. First, the Measles, Mumps and Rubella vaccine, known as MMR, is only 88 percent effective against mumps after the second dose.

And health officials have also noted a waning immunity as people get older.

“Even if you get an MMR vaccine, by the time you get around to college the vaccine starts to wane,” Vogt said. “And it’s not 100 percent effective already.”

Couple an 88 percent effectiveness rate with shrinking immunity in a college setting — where students stay in close quarters during most of the day, living in dormitories, playing sports and socializing — and outbreaks seem all the more likely.

Virginia isn’t alone in seeing these rising numbers. Since 2016, there’s been a surge in the number of mumps cases across the country, especially in places where people have close contact with each other, like college campuses.

According to the Centers for Disease Control and Prevention, the number of mumps cases nationally shot up from 229 in 2012 to 6,366 in 2016.

Though those numbers are still far smaller than the 186,000 cases reported every year before the U.S. began its mumps vaccination program in 1967, the sudden surge has caught the attention of health officials who have changed their vaccine recommendations in an effort to tackle the problem.

At James Madison University, the Virginia Department of Health recommended students receive a third dose of the MMR vaccine during the outbreak that occurred early this year. Typically it is first given at 12 months and then again between the ages of 4 and 6.

“You can use a third dose of the MMR vaccine to help control outbreaks,” Vogt said. “You get the immunity level back up so it’s not able to make its way through students.”

Earlier this year the CDC changed its guidelines in response to all the outbreaks, after the Advisory Committee on Immunization Practices studied the issue last year.

But the third-dose recommendation applies only to those who public health officials have identified as at-risk because of an outbreak. The CDC hasn’t yet changed its guidelines for the general public, who still typically get only two doses of the vaccine.

Vogt said it would probably take a few years of studying the vaccine and immune response before the CDC would make that broad of a recommendation.