The number of mumps outbreaks in the U.S. has risen sharply in recent years. From
2012-’15, a total of 47 outbreaks were reported. In contrast, there were 50 outbreaks
in 2016 and 88 in 2017.
Outbreaks have occurred in closely congregated settings, such as college campuses
and close-knit communities based on shared religious or cultural interests. These
outbreaks are occurring despite a large number of infected individuals having received
the recommended two-dose series of mumps-containing vaccinations. The reason for this
increase among fully vaccinated individuals is unclear.
In response to these mumps outbreaks, the CDC convened a panel of experts from nine
national organizations and specialties, including the AAP. The group met for 15 months
and reviewed data on mumps epidemiology, duration of immunity after the recommended
two-dose series and the impact of a third dose of vaccine on outbreak control and
public health resources.
The CDC working group found that data are insufficient to recommend routine use of
a third dose of mumps-containing vaccine to shorten the duration of an ongoing mumps
outbreak. However, the group stated that public health officials can recommend a third
dose of mumps-containing vaccine to provide protection against mumps infection and
When administered during an outbreak, a third dose of mumps vaccine is safe and appears
to reduce the risk of infection and the severity of disease in people at high risk
of infection. To determine whether to recommend a third dose of vaccine, public health
officials will use a risk-based matrix to identify at-risk communities and individuals.
The working group did not recommend a third dose of mumps-containing vaccine outside
a mumps outbreak.
Pediatric health care professionals should be aware that children and young adults
involved in mumps outbreaks may come to them after being notified by public health
officials that they should receive a third dose of mumps-containing vaccine. Providers
also may want to communicate with local public health officials if they become aware
of mumps cases in their practice.
Mumps virus is spread from person to person through respiratory secretions and is
characterized by swelling of salivary, or parotid, glands. Accompanying symptoms include
fever, headache, fatigue and myalgias. The most well-known complication of mumps infection
is swelling of the testicles (orchitis), which may occur in up to one-third of post-pubertal
males and rarely can lead to long-term fertility problems.
The incidence of mumps disease has been reduced markedly since the implementation
of childhood mumps vaccination. In addition, vaccination has been shown to reduce
the severity of mumps infection.
Dr. Nolt is a member of the AAP Committee on Infectious Diseases.