In the mid-twentieth century, mumps infections among children were not viewed as a serious public health issue, but adult men may develop debilitating testicular inflammation, which posed particular difficulty among close-quartered soldiers during wartime. As a result, during World War II (1939-1945), the United States government targeted mumps for scientific research.^[4] The first experimental mumps vaccine was licensed in 1948; developed from inactivated virus, it only had short-term effectiveness.^[3]

Improved vaccines became commercially available in the 1960s.^[1] In 1963, Maurice Hilleman of Merck & Co. took samples of the mumps virus from his daughter, who had contracted the disease; she became the namesake for the resulting Jeryl Lynn strain.^[4][5] Building on then-recent advances that had led to vaccines for polio and measles, the mumps virus strains were developed in embryonic hens' eggs and chick embryo cell cultures.^[4] The resulting strains of virus were less well-suited for human cells, and are thus said to be attenuated. They are sometimes referred to as neuroattenuated in the sense that these strains are less virulent to human neurons than the wild strains.^[6][7]

Hilleman's work led to the first effective mumps vaccine, called Mumpsvax. Licensed in 1967, its four-year development set a record for fastest development of a new vaccine,^[4] a record later surpassed by the COVID-19 vaccine, which was developed in less than a year.^[8]

Vaccination against mumps did not become routine until Mumpsvax was included in Merck's combined MMR vaccine, which targeted measles and rubella along with mumps.^[4][2][9] MMR was licensed in 1971, and 40 percent of American children had received the combined vaccine by 1974. In 1977, the U.S. Centers for Disease Control and Prevention (CDC) recommended mumps immunization (as part of MMR) for all children over 12 months of age, and in 1998, CDC began recommending a two-dose immunization of MMR.^[4]

While the initial vaccine in the 1940s was based on inactivated virus, subsequent preparations since the 1960s consist of live virus that has been weakened.^[1] Mumps vaccine is on the World Health Organization's List of Essential Medicines.^[10][11] There are a number of different types in use as of 2007.^[1]

Mumpsvax is Merck's brand of Jeryl Lynn strain vaccines.^[12][13] It is a component of Merck's three-virus MMR vaccine, and is the mumps vaccine standard in the United States.^[14] Mumpsvax is given by a subcutaneous injection of live virus reconstituted from freeze-dried (lyophilized) vaccine.^[13] Production of Mumpsvax as a stand-alone product ceased in 2009.^[15][16]

The cells used in culture, virus stocks used, and animal fluids are all screened for extraneous material as part of the vaccine production. They are grown in Medium 199 (a solution containing buffered salt, vitamins, amino acids, fetal bovine serum) with SPGA (sucrose, phosphate, glutamate, human serum albumin) and neomycin. The human albumin processing uses the Cohn cold ethanol fractionation method.^[13]

Other types edit

• RIT 4385 is a newer strain derived from the Jeryl Lynn strain^[2] by Maurice Hilleman, Jeryl Lynn's father.
• Leningrad-3 strain was developed by Smrodintsev and Klyachko in guinea pig kidney cell culture and has been used since 1950 in former Soviet countries.^[17] This vaccine is routinely used in Russia.
• L-Zagreb strain used in Croatia and India was derived from the Leningrad-3 strain by further passaging.^[17]
• Urabe strain was introduced in Japan, and later licensed in Belgium, France and Italy. It has been associated with a higher incidence of meningitis (1/143 000 versus 1/227 000 for J-L),^[18] and abandoned in several countries. It was formulated as MMR in the UK.
• Rubini strain used mainly in Switzerland was attenuated by a higher number of passes through chicken embryos, and later proved to have low potency.^[19] It was introduced in 1985.^[17]

Monovalent mumps vaccine (Mumpsvax) remained available in the US when MMR was introduced in the UK, replacing the MR (measles and rubella) mixed vaccine. No UK-licensed monovalent preparation was ever available.^[20] Monovalent mumps vaccines were available before MMR, but only used on a limited scale.^[21][22] This became the subject of considerable argument at the end of the 20th century, since some parents preferred to obtain individually the components of the MMR mixture. One mumps vaccine preparation imported into the United Kingdom and unlicensed, proved to be essentially ineffective.^[23] Immunisation against mumps in the UK became routine in 1988, commencing with MMR. The Aventis-Pasteur "MMR-2" brand is usual in the UK in 2006^{[citation needed]}.

The cold chain is a major consideration in vaccination, particularly in less-developed countries. Mumps vaccines are normally refrigerated, but have a long half-life of 65 days at 23 degrees Celsius.^[17]

• Mumps Vaccine at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
• "Mumps Vaccine". Drug Information Portal. U.S. National Library of Medicine.
• Mumps (The History of Vaccines)
• Mumps Immunization. WHO