Talking About Vaccines with Dr. Paul Offit: News Briefs – April 2017 – Mumps Outbreak

News Briefs — Mumps Outbreak

Dr. Paul Offit: Hi, my name is Paul Offit, I’m talking to you today from the Vaccine Education Center at the Children's Hospital of Philadelphia. It’s Friday, April 21, 2017, and what I thought I’d talk about is mumps. Last year, in the United States, there were more than 5,000 cases of mumps. So, let’s figure out why that happened.

In order to do that we’ll start at the beginning. Now, the original mumps vaccine, the one that was created in 1967, was actually recommended universally for all children starting at 12 months of age 10 years later, in 1977. And then because of continued outbreaks, primarily of measles, the second dose of mumps vaccine was recommended in 1989 along with the measles and rubella vaccines in the combination vaccine MMR. So basically in 1977, you had one dose of mumps vaccine recommended. By 1989 there were now two doses of mumps vaccines that were recommended.

Yet still, we had 5,000 cases, more than 5,000 cases of mumps last year. So what’s happened? The surprising thing is if you look at those cases, most of those children had already received two doses of mumps vaccine. The problem with mumps vaccine as distinct from measles and rubella vaccines is that the immunity to mumps vaccine can fade. So 10 years after dose one, which came out in 1977, you started to see children develop mumps—10 years after the first dose. Now, 10 years after the second dose, so now you’re looking at late adolescence and young adulthood, you’re seeing cases of mumps develop because mumps immunity fades. Measles immunity doesn’t. And so, as a consequence, we were able to eliminate measles in the United States by the year 2000. Rubella immunity doesn’t fade either. That’s why we were able to eliminate rubella by the year 2005, but we’ve never eliminated mumps from the United States, and I think it’s going to be hard to do that.

What I think the answer to this question is going to be probably you’re going to see a third dose of mumps vaccine recommended, probably in adolescents around 11 to 13 years of age. The Centers for Disease Control and Prevention, or CDC, has formed a working group to answer that question, and I think that question will probably be answered in the next few years.

When the CDC originally presented their data of 5,000 cases, it was reassuring that people who develop mumps after two doses of mumps vaccines, although they developed the swelling of the parotid glands here at the angle of the jaw, which are salivary glands, didn’t seem to develop the complications of mumps, which is to say orchitis, which is inflammation of the testes that can lead to sterility; or aseptic meningitis, which is a viral infection of the lining of the brain and spinal cord, which can cause things like hearing loss.

A recent outbreak of mumps in Iowa, involving University of Iowa, involving about 300 students, showed that those side effects could occur. There was a case of sensory neural hearing loss. There was a case of aseptic meningitis. There was a case of orchitis, and it looked like it was occurring in about 7 percent of those who were infected. So we’ll see. I think that probably our best bet right now is to have a third dose of mumps vaccine given in adolescence, and I think we’re going to know about that in the next year or two. Thank you.