It is not news that we have been seeing more cases of mumps in recent years.
It is also isn’t news that many of these folks are vaccinated.
“Long Beach has been hit with a mumps outbreak that is vaccine-resistant. According to health officials in the Long Island town, almost two dozen individuals are believed to have contracted the virus, with four confirmed cases and at least 14 suspected ones.”
Why Do Folks Think That Vaccine-Resistant Viruses Are Causing Mumps Outbreaks?
So are vaccine-resistant mumps viruses causing outbreaks?
Unfortunately, it might not be surprising that some folks are confused about vaccine-resistant mumps viruses, when we have health officials saying things like:
“Sometimes nature throws a strain at us that might have mutated a little bit, and coverage of the vaccine is not 100 percent.”
Dr. Lawrence Eisenstein, Nassau County Health Commissioner
Dr. Eisenstein’s “might have mutated a little bit” comment got twisted into “the outbreak is most likely attributable to a new strain of the virus that is resistant to vaccines” by health reporters
And out of Arkansas, where there have also been large mumps outbreaks:
“We are actually to the point that we are worried that this vaccine may indeed not be protecting against the strain of mumps that is circulating as well as it could.”
Dr. Dirk Haselow, Arkansas State Epidemiologist
Of course, to say that the vaccine may not be protecting folks “as well as it could” doesn’t mean it doesn’t work because the wild type mumps virus has evolved or mutated enough to surmount our current MMR vaccine.
Is Mutating Mumps More Than the MMR Can Manage?
Although anything is possible, we fortunately have plenty of research that says that the mumps virus hasn’t mutated and that the MMR still works.
In fact, although the MMR vaccine is made from the A strain or genotype of mumps, it provides good protection against all 12 known strains of wild mumps viruses, including genotype G that has been causing most of the recent outbreaks.
But how can it cover a different strain of virus that isn’t in the vaccine?
Because not all viruses and vaccines are like influenza.
“The genotyping of the mumps virus is based on the Small Hydrophobic (SH) protein, a nonstructural protein and genetically the most variable one. Based on the SH-protein 12 different mumps viruses were detected up to now. In recent epidemics in Western countries the genotype G was mainly detected, while the mumps viruses used in the live attenuated mumps vaccines belong to genotype A (Jeryl Lynn) and to a lesser extent to genotype B (Urabe). However, antibodies against the SH protein have not yet been observed in human serum. It is, therefore, unlikely that antibodies against the SH protein play an important role in antibody-mediated virus neutralization.”
Sabbe et al. on The resurgence of mumps and pertussis
It is well known that you need a very specific match of the flu vaccine to the wild flu virus that is going around to get good protection, but for many other viruses, the differences that determine the strain or genotype have nothing to do with how antibodies will recognize the virus.
“Since mumps virus is monotypic, vaccine from any strain should provide lifelong protection against subsequent infection.”
Palacios et al. on Molecular Identification of Mumps Virus Genotypes from Clinical Samples: Standardized Method of Analysis
Like measles, mumps is a monotypic virus.
“Studies have demonstrated that blood sera from vaccinated persons cross-neutralizes currently circulating mumps strains.”
CDC on Mumps for Healthcare Providers
And like measles, the mumps vaccine (MMR), protects against all strains of wild mumps viruses.
“Compared with attack rates of 31.8%–42.9% among unvaccinated individuals, attack rates among recipients of 1 dose and 2 doses of the Jeryl Lynn vaccine strain were 4%–13.6% and 2.2%–3.6%, respectively.”
Dayan et al. on Mumps Outbreaks in Vaccinated Populations: Are Available Mumps Vaccines Effective Enough to Prevent Outbreaks?
And like other vaccines, the mumps vaccine (MMR) works.
What to Know About Mumps Strains and Outbreaks
The MMR vaccines covers all strains of mumps and getting fully vaccinated is the best way to make sure your kids don’t get mumps.
More on Mumps Strains and Outbreaks
- Study – Antibody induced by immunization with the Jeryl Lynn mumps vaccine strain effectively neutralizes a heterologous wild-type mumps virus associated with a large outbreak.
- Study – Differences among mumps virus surface proteins between genotype G and other genotypes and their potential effect on mumps virus immunity and pathogenesis
- Study – Recent mumps outbreaks in vaccinated populations: no evidence of immune escape.
- Update on Mumps Outbreak: Arkansas
- Social Media, Math And The Mystery Of A Mumps Outbreak
- The resurgence of mumps and pertussis
- Nassau County Department of Health Investigating An Increased Incidence of Mumps
- New York: Mumps increase reported in Nassau County
- At Least 18 Suspected Mumps Cases in Long Island Outbreak: Officials
- Mumps outbreak sweeps Long Beach; affected residents had already been vaccinated
- WHO – The Immunological Basis for Immunization: Mumps
- CDC – Mumps Cases and Outbreaks
- CDC – Questions and Answers about Mumps Lab Testing
- CDC – Mumps for Healthcare Providers
- Study – Mumps Epidemiology and Mumps Virus Genotypes Circulating in Mainland China during 2013-2015
- Study – Antigenic relationships between six genotypes of the small hydrophobic protein gene of mumps virus.
- Study – Mumps Outbreaks in Vaccinated Populations: Are Available Mumps Vaccines Effective Enough to Prevent Outbreaks?
- Genotypes, Serotypes and the MMR: Cognitive Dissonance in Action
- Study – Genetic Characterization of Measles Vaccine Strains
- Report – Global Distribution of Measles Genotypes and Measles Molecular Epidemiology
- Measles Surveillance Data
- Diagnosing Mumps: Don’t Be So Sure
- Study – Etiology of mumps-like illnesses in children and adolescents vaccinated for measles, mumps, and rubella.
- Study – Difficulty with mumps diagnosis: what is the contribution of mumps mimickers?
- Study – Viruses detected among sporadic cases of parotitis, United States, 2009-2011.
- Study – Characteristics of a large mumps outbreak: Clinical severity, complications and association with vaccination status of mumps outbreak cases
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