Editing Mumps (section)

==History==
According to Chinese medical literature, mumps was recorded as far back as 640 B.C.<ref name=shu /> The [[Greeks|Greek]] physician [[Hippocrates]] documented an outbreak on the island of [[Thasos]] in approximately 410 B.C. and provided a fuller description of the disease in the first book of ''Epidemics'' in the [[Corpus Hippocraticum]].<ref name=rubin /><ref name=history >{{cite web |url=https://www.pharmaceutical-technology.com/features/tracing-story-mumps-timeline/ |title=Tracing the story of mumps: a timeline |author=<!--Not stated--> |website=Pharmaceutical Technology |date=25 April 2018 |publisher=Pharamaceutical Technology |access-date=30 October 2020}}</ref> In modern times, the disease was first described scientifically in 1790 by British physician Robert Hamilton in ''Transactions of the Royal Society of Edinburgh''.<ref>{{cite journal |vauthors=Hamilton R |date=1790 |title=IX. ''An'' Account of a Distemper, ''by the common People in England vulgarly called the MUMPS'' |journal=Transactions of the Royal Society of Edinburgh |volume=2 |issue=2 |pages=59–72 |doi=10.1017/S0263593300027280 |pmid=29139995 |pmc=5550187}}</ref> During the [[First World War]], mumps was one of the most debilitating diseases among soldiers.<ref>{{cite web |url=https://www.worldwar1centennial.org/index.php/diseases-in-world-war-i.html |title=Diseases in World War I |vauthors=Van-Way CW, Marble WS, Thompson G |website=The United States World War I Centennial Commission |publisher=United States Foundation for the Commemoration of the World Wars |access-date=30 October 2020 }}</ref> In 1934, the etiology of the disease, the mumps virus, was discovered by Claude D. Johnson and Ernest William Goodpasture. They found that [[rhesus macaque]]s exposed to saliva taken from humans in the early stages of the disease developed mumps. Furthermore, they showed that mumps could then be transferred to children via filtered and sterilized, bacteria-less preparations of macerated monkey parotid tissue, showing that it was a viral disease.<ref name=rubin /><ref name=history />

In 1945, the mumps virus was isolated for the first time. Just a few years later, in 1948, an [[inactivated vaccine]] using killed viruses was invented. This vaccine provided only short-term immunity and was later discontinued. It was replaced in the 1970s with vaccines that have live but weakened viruses, which are more effective at providing long-term immunity than the inactivated vaccine. The first of these vaccines was Mumpsvax, licensed on 30 March 1967, which used the Jeryl Lynn strain. [[Maurice Hilleman]] created this vaccine using the strain taken from his five-year-old daughter, Jeryl Lynn. Mumpsvax was recommended for use in 1977, and the Jeryl Lynn strain continues to be used.<ref name=ramanathan /><ref name=history />

Hilleman worked to combine the attenuated mumps vaccines with the measles and rubella vaccines, creating the MMR-1 vaccine. In 1971, a newer version, MMR-2, was approved for use by the US [[Food and Drug Administration]].<ref name=ramanathan /> In the 1980s, the benefit of multiple doses was recognized, so a two-dose immunization schedule was widely adopted.<ref name=ramanathan /><ref name=peltola /> With MMR-2, four other MMR vaccines have been created since the 1960s: Triviraten, Morupar, Priorix, and Trimovax. Since the mid-2000s, two MMRV vaccines have been in use: Priorix-Tetra and ProQuad.<ref name=su />

The United States began to vaccinate against mumps in the 1960s, with other countries following suit.<ref name=rubin /> From 1977 to 1985, 290 cases per 100,000 people were diagnosed each year worldwide.<ref name=davis /> Although few countries recorded mumps cases after they began vaccination, those that did reported dramatic declines. From 1968 to 1982, cases declined by 97% in the U.S., and in Finland cases were reduced to less than one per 100,000 people per year,<ref name=beleni /> and a decline from 160 cases per 100,000 to 17 per 100,000 per year in England was observed from 1989 to 1995.<ref name=demicheli /> By 2001, there had been a 99.9% reduction in the number of cases in the U.S. and similar near-elimination in other vaccinating countries.<ref name=rubin />

In Japan in 1993, concerns over the rates of aseptic meningitis following MMR vaccination with the Urabe strain prompted the removal of MMR vaccines from the national immunization program, resulting in a dramatic increase in the number of cases.<ref name=su /><ref name=rubin /> Japan provides voluntary mumps vaccination separately from measles and rubella.<ref name=japan /> Starting in the mid-1990s, controversies surrounding the MMR vaccine emerged. One paper connected the MMR vaccine to [[Crohn's disease]] in 1995, and another in 1998 connected it to [[autism spectrum]] disorders and [[inflammatory bowel disease]]. These papers are now considered to be fraudulent and incorrect, and no association between the MMR vaccine and the aforementioned conditions has been identified. Despite this, their publication led to a significant decline in vaccination rates, ultimately causing measles, mumps, and rubella to reemerge in places with lowered vaccination rates.<ref name=davis /><ref name=masarani /><ref name=history />

Outbreaks in the 21st century include more than 300,000 cases in China in 2013<ref name=shu /> and more than 56,000 cases in England and Wales in 2004–2005. In the latter outbreak, most cases were reported in 15–24 year olds who were attending colleges and universities. This age group was thought to be vulnerable to infection because of the MMR vaccine controversies when they should have been vaccinated or MMR vaccine shortages that had also occurred at that time.<ref name=davis /> Similar outbreaks in densely crowded environments have frequently occurred in many other countries, including the U.S., the Netherlands, Sweden, and Belgium.<ref name=ramanathan />

===Resurgence===
{| class="wikitable" align=right style="margin:1em"
|+ Select mumps outbreaks exceeding 1,000 cases in vaccinating locations<ref name=ramanathan />
! Year(s) !! Location !! Number of cases
|-
| 2005–2006 || Czech Republic || 5,998
|-
| 2006 || U.S. || 6,584
|-
| 2009 || New York (U.S.) || 1,521
|-
| 2009–2011 || Jerusalem || 3,130
|-
| 2012–2013 || Belgium || 4,061
|-
| 2013 || Poland || 2,436
|-
| 2014 || U.S. || 1,151
|-
| 2016–2017 || Arkansas (U.S.) || 2,706
|-
| 2017 || U.S. || 5,629
|}

In the 21st century, mumps has reemerged in many places that vaccinate against it, causing recurrent outbreaks. These outbreaks have largely affected adolescents and young adults in densely crowded spaces, such as schools, sports teams, religious gatherings, and the military, and it is expected that outbreaks will continue to occur. The cause of this reemergence is subject to debate, and various factors have been proposed, including waning immunity from vaccination, low vaccination rates, vaccine failure, and potential [[antigenic variation]] of the mumps virus.<ref name=su /><ref name=rubin /><ref name=ramanathan /><ref name=beleni />

Waning immunity from vaccines is likely the primary cause of the mumps resurgence. In the past, subclinical natural infections provided boosts to immunity similar to vaccines. As time went on with vaccine use, these asymptomatic infections declined in frequency, likely leading to a reduction in long-term immunity against mumps. With less long-term immunity, the effects of waning vaccine immunity became more prominent, and vaccinated individuals have frequently fallen ill from mumps. A third dose of the vaccine provided in adolescence has been considered to address this as some studies support this. Other research indicates that a third dose may be useful only for short-term immunity in responding to outbreaks,<ref name=latner /><ref name=ramanathan /> which is recommended for at-risk persons by the [[Advisory Committee on Immunization Practices]] of the [[Centers for Disease Control and Prevention]].<ref name=su />

Low vaccination rates have been implicated as the cause of some outbreaks in the UK, Canada, Sweden, and Japan, whereas outbreaks in other places, such as the U.S., the Czech Republic, and the Netherlands, have occurred mainly among the vaccinated. Compared to the measles and rubella vaccines, mumps vaccines appear to have a relatively high failure rate, varying depending on the vaccine strain. This has been addressed by providing two vaccine doses, supported by recent outbreaks among the vaccinated having primarily occurred among those who received only one dose. Lastly, certain mumps virus lineages are highly divergent genetically from vaccine strains, which may cause a mismatch between protection against vaccine strains and non-vaccine strains, though research is inconclusive on this matter.<ref name=su /><ref name=ramanathan />