This transcript has been edited for clarity.
Hi. My name is Paul Offit. I'm talking to you today from the Vaccine Education Center at Children's Hospital of Philadelphia. What I want to talk about is something that's going on in Philadelphia right now, which is a mumps outbreak at Temple University. As of this morning, there have been 99 reported cases of mumps. Mumps have been reported at Drexel University, also in Philadelphia, and at Westchester University, which is just outside the city.
What's going on? Let's start at the beginning.
The mumps vaccine was originally developed in the United States in 1967 by Dr Maurice Hilleman. At the time, about 200,000 cases of mumps were reported, and that was probably a low estimate of what was really going on. Mumps is not a trivial disease. It can affect the parotid glands and cause pain when trying to eat, but it also can affect the testes, causing orchitis, which can lead to sterility. It can affect the ovaries, causing oophoritis, which also can lead to sterility. So it's not a trivial infection.
Because of the mumps vaccine, we went from about 200,000 to about 200 cases a year. But mumps has never been eliminated, and that's different from the measles and rubella components of the MMR vaccine. Measles was eliminated from the United States in 2000, and the only reason measles has come back in this country is because a critical number of parents have chosen not to vaccinate their children. Rubella also was eliminated in this country in 2005 and has not yet come back.
Mumps was never eliminated. The reason is, if you go back and look at those early studies, there were far greater frequencies of memory B and T cells following measles and rubella immunization than following mumps immunization. What we've seen clinically is consistent with that. Roughly 10 years after the first dose recommendation in the late 1960s, there was a reduction in mumps. But clearly, after vaccine memory (immunity) started to fade, there was a recommendation for a second MMR dose in 1991, primarily for the measles component. The second dose recommendation was for 4- to 6-year-olds, so 10 years later, roughly in late adolescence or early adulthood, you would start to see mumps return because of fading immunity.
Last year we had about 6000 cases of mumps in the United States. Many were associated with college outbreaks, because that's about 10 years after the second dose.
The recommendation from the Centers for Disease Control and Prevention is to get a third dose of mumps vaccine if you are on a college campus or in a setting where there is an outbreak. We may be moving toward a third dose recommendation anyway, if these outbreaks continue among 16- to 18-year-olds. Thank you for your attention.
Medscape Infectious Diseases © 2019 WebMD, LLC
Any views expressed above are the author's own and do not necessarily reflect the views of WebMD or Medscape.
Cite this: Paul A. Offit. What Will It Take to Eradicate Mumps? - Medscape - Apr 04, 2019.