ACIP recommends third MMR dose during mumps outbreaks
The Advisory Committee on Immunization Practices, or ACIP, voted unanimously in favor of a third dose of the measles-mumps-rubella vaccine for individuals at risk during a mumps outbreak.
This vote is in response to a drastic rise in mumps outbreaks since 2006, most notably among college students with high rates of immunization, many of whom had received both recommended doses of the measles-mumps-rubella (MMR) vaccine. Despite the highly-immunized populations, 50% of outbreaks and 40% of all cases in 2016 took place on college campuses.
During a presentation on mumps epidemiology, Mona Marin, MD, from the Division of Viral Diseases at the CDC, noted that the crowded living conditions on college campuses — in particular, those found among fraternities, sororities and sports teams — contributed significantly to recent outbreaks.
“Mumps outbreaks continue to be a public health burden, and young adults are at highest risk,” she said in her presentation. “Although half of all outbreaks were less than 10 cases, 13% of outbreaks had 50 or more mumps cases, which accounted for over 80% of all cases.”
The CDC has not changed its vaccination recommendations for the general population, as the current two-dose MMR schedule — considered 88% effective at preventing mumps — appears to be sufficient in controlling mumps outside of high-risk populations. Although the CDC has offered guidance for health departments on administering a third MMR dose during outbreaks since 2012, Marin said that a recommendation from the ACIP would give clearer direction to stakeholders.
During the presentation, Mariel Marlow, PhD, MPH, also from the CDC’s Division of Viral Diseases, said that while current data are limited regarding whether a third dose can prevent complications due to mumps, the evidence shows that it is safe and the risk for serious adverse events is low.
Marlow also mentioned research showing that a third dose provides short-term increases in antibodies and that minor adverse events, including joint problems, headache, diarrhea and swollen glands, were experienced at low rates.
According to data cited at the meeting, attack rates among at-risk populations were lower in those who have received a third dose (P < .001).
In addition, survey results revealed that 85% of students and 80% of parents reported having positive attitudes toward the recommendation for a third dose.
“I like this recommendation because it seems as though it is for individual protection and for outbreak control,” Adria Lee, MSPH, from IHRC Inc., a contracting agency to the CDC’s Division of Viral Diseases, said prior to the vote. – by Katherine Bortz
Disclosures: Infectious Disease News was unable to confirm relevant financial disclosures at the time of publication.