Summaries of Must-Read Clinical Literature, Guidelines, and FDA Actions
Vaccine Waning and Mumps Re-emergence in the US
Sci Transl Med; ePub 2018 Mar 21; Lewnard, Grad
Routine use of a third vaccine dose at age 18, or booster dosing throughout adulthood, may be a strategy to prevent mumps re-emergence and should be assessed in clinical trials, a recent study found. After decades of declining mumps incidence amid widespread vaccination, the US and other developed countries have experienced a resurgence in mumps cases over the last decade. Synthesizing data from 6 studies of mumps vaccine effectiveness, researchers estimated that vaccine-derived immune protection against mumps wanes on average 27 years after vaccination. They also found:
- After accounting for this waning, there was no evidence that the emergence of heterologous virus genotypes contributed to changes in vaccine effectiveness over time.
- Outbreaks from 2006 to present date among young adults, and outbreaks in the late 1980s and early 1990s among adolescents, aligned with peaks in mumps susceptibility of these age groups predicted to be due to loss of vaccine-derived protection.
- In contrast, evolution of mumps virus strains escaping immune pressure would be expected to cause a higher proportion of cases among children, not adolescents and young adults as observed.
Lewnard JA, Grad YH. Vaccine waning and mumps re-emergence in the United States. [Published online ahead of print March 21, 2018]. Sci Transl Med. doi:10.1126/scitranslmed.aao5945.
Although outbreaks of mumps have significantly declined since routine mumps vaccination, mumps outbreaks continue even in highly vaccinated populations. Theories regarding the cause of the mumps outbreaks include waning immunity in the population, lack of immune response to the vaccine, or emergence of new mumps viral strains not prevented by the current vaccine. This sophisticated study looked at the data on recent mumps outbreaks and used the data to model the different theories. The data fit the model that outbreaks are likely associated with waning immunity over time (average 27 years) and suggest that a third vaccine dose may reduce mumps outbreaks in the future.—Sarah Rawstron, MB, BS, FAAP, FIDSA
Pediatric Residency Program Director, The Brooklyn Hospital Center, NY
Clinical Associate Professor, Icahn School of Medicine, Mount Sinai, NY