a 10-year high in the U.S., jumping from
229 cases in 2012 to more than 4,000 in
2016. A vaccine-preventable disease that
affects the salivary glands, mumps causes
headaches, fatigue, and swelling of the jaw;
in rare cases, it can lead to complications
including deafness or brain inflammation.
Infections were reported in 46 states and
the District of Columbia last year; particularly
hard hit were Arkansas, Iowa,
Indiana, Illinois, Massachusetts, New York,
and Oklahoma. Health officials have noted
that the controversial “anti-vax” movement,
which opposes the use of vaccinations,
isn’t entirely to blame: Most of the
people diagnosed with mumps last year
had received the two recommended
doses of the measles-mumps-rubella
(MMR) vaccine. There is also no evidence
that the virus has mutated, which
would render the vaccine less effective.
“The most likely reason for these
outbreaks is that vaccine immunity
is fading,” Dr. Paul Offit, with the
Children’s Hospital of Philadelphia,
tells Scientific American. Health
officials investigating the issue say a
third dose of the MMR vaccine may
be required.
