Measles, mumps and rubella
Manufacturer’s Inserts and efficacy statements: MMR II (live virus)-Package Insert states efficacy is based on the individual vaccine components.
*Per The CDC: The vaccine effectiveness for one dose of MMR is 70-80% and 80-90% for two doses.
The levels of antibody against measles, mumps, and rubella were determined at 5–6 years postimmunization in 468 children vaccinated with two different trivalent vaccines. The proportions of children without detectable antibody levels were 12 and 3.6% for measles (p<0.001), 14.9 and 7% for mumps (p=0.006), and 3.3 and 3.1% for rubella (p=0.88), respectively, in MMR® II and Trivirix® recipients. A higher proportion of those vaccinated at younger ages had undetectable or low levels of measles antibody. These data indicate that a large proportion of children vaccinated under routine conditions do not have detectable measles and mumps antibody.
A study completed in England judged the effectiveness of the MMR to be an average of 69% (given a range of 41-84%). Researchers in this study further note:
This is consistent with the results of other observational studies of mumps containing vaccines, but lower than the immunogenicity of mumps vaccines reported by clinical trials.
Mumps outbreaks across England and Wales in 2004: observational study notices that despite beginning routine vaccination with the MMR in 1988:
In 1999, numbers of cases of mumps in teenagers in England and Wales began to rise. We report a further increase in the incidence of mumps in 2004.
The mumps component of the MMR vaccine used in the UK is believed to offer around 90% protection for one dose, although recent reports indicate that this could be as low as 64%.
In America,the meeting notes of the Advisory Committee on Immunization Practices, Centers for Disease Control and Prevention, October 25-26, 2006 addresses similar concerns. Isolation of the mumps virus from the epidemic revealed that it was the G. genotype; identical to the virus involved in the United Kingdom outbreak. Of the college students involved, 93%-100% had been fully vaccinated with 2 doses of MMR.
Questions that remain regarding the collagen outbreak:
1. Is mumps circulating endemically and is there a high accumulation of susceptibles due to vaccine failure?
2. Would a third dose of MMR be useful for outbreak prevention?
3. Can mumps be eliminated using the current MMR vaccine?
It was further noted that there had been no spread to the unvaccinated population.