CDC Pinkbook Mumps

In the pre-vaccination times, 15-27% of cases of mumps were asymptomatic, and how many cases are currently unknown, since it is not clear how the vaccine changes clinical symptoms. Orchitis (inflammation of the testicle) is the most common complication of mumps, but it is only possible Sexually mature men, usually orchitis is one-sided.Infertility from swine orchitis occurs rarely, even in the case of bilateral orchitis.
Before the vaccine appeared, no mumps diseases were recorded.
Monovalent vaccine t pig is almost nowhere to be found, except in Japan, where the MMR is still banned, and where the state vaccine against mumps is not sponsored by, and from the few who instilled.


A retrospective survey of the complications of mumps. 1974, J R Coll Gen Pract

2,482 cases of hospitalization from mumps are analyzed here in 1958-1969 in 16 hospitals in England, they constitute the majority of the cases of mumps requiring hospitalization in the country, half of the patients were older than 15. Complications were observed in 42%. two of them had another serious illness, and the mumps might not have been related to death, and the third probably had no mumps, and the only complication that may have remained irreversible among these cases is deafness in five patients, four of them adults. About Me the agitation in mumps happens so often that some people think that it should not be considered a complication, but an integral part of the disease. In any case, there is a consensus that meningitis in mumps is not dangerous and it rarely has consequences. What is commonly feared is orchitis, there is a general fear of infertility from orchitis, but the likelihood of this is overestimated, although infertility can not be ruled out, in a small retrospective study infertility, as a consequence of orchitis, would not to found.
authors conclude that mass vaccination against mumps is not necessary. Maybe it makes sense to vaccinate sexually mature adolescents on admission to a boarding school or army. But even then it should be remembered that 90% of boys by the age of 14 already had a mumps, so they should check the antibodies, and vaccinate only those who have no antibodies.


Waning immunity against mumps in vaccinated young adults, France 2013. 2016, Vygen, Euro Surveill

In 2013, 15 outbreaks of mumps were registered in France, 72% of the cases were vaccinated twice, the effectiveness of the vaccine was 49% for one dose, and 55% for two doses. Among those who were vaccinated once, with each past year after vaccination, the risk of developing mumps increased by 7%.
Among those who were vaccinated twice, with each passing year after vaccination, the risk of getting mumps increased by 10%.
Five men there was an orchitis, one was unprivileged, two were vaccinated with a single dose, and two were vaccinated twice.
Pig is a mild illness that but it can sometimes lead to serious complications, such as orchitis, meningitis, pancreatitis or encephalitis, especially among adults. In adults, complications from mumps are more common, and these complications are more serious than in children, especially among the unvaccinated. In other countries, outbreaks of mumps among vaccinated people are also observed, the reason for this is the diminishing effectiveness of the vaccine, and in the absence of natural boosters. It is also possible that outbreaks are primarily to blame for the overestimated effectiveness, inadequate vaccination coverage, or the presence of a strain that is not covered by the vaccine.
The presence of outbreaks among vaccinated and falling effectiveness make one think about a third dose of the vaccine. Such an experiment was conducted in the USA during the outbreaks in 2009 and 2010. Both times the outbreak receded a few weeks after vaccination. However, outbreaks always go to waste, and it is unclear whether this was due to the vaccine. Nevertheless, this and other experiments hint that the third dose of a vaccine is a good idea. In addition, during the vaccination campaigns in the United States, the third dose showed few side effects.
The Netherlands wanted to introduce a third dose of MMR into the national vaccination schedule, but changed their mind, because, firstly, the mumps rarely get complications, and secondly, it is unlikely that vaccination coverage among adults will be satisfactory.
Outbreaks of mumps among vaccinated, as well as this study, led to the fact that the Ministry of Health of France recommended doing a third dose of MMR during outbreaks. Despite the fact that it is not known whether the vaccine is effective for those already infected with the virus, it is possible that vaccination will reduce the period of infectiousness of the vaccinated.
In a Dutch study, it was found that two-thirds sick during outbreaks asymptomatically. The role of asymptomatic patients in the transmission of the disease remains unknown.
Future observations in France, and possibly also in other countries that adopt such a recommendation, will help determine whether the third dose of MMR is effective during outbreaks.


Mumps vaccine associated orchitis: Evidence supporting a potential immune-mediated mechanism. 2010, Clifford, Vaccine

Orchitis may well arise as a result of vaccination against mumps:

[1] 2014, Kanda, Int J Urol
[3] 1994, Kuczyk, Urol Int
[2] 2008, Abdelbaky, Ann R Coll Surg Engl
[4] 2002, Suzuki, Jpn J Urol