Mumps vaccine

Mumps vaccines are vaccines which prevent mumps. When given to a majority of the population they decrease complications at the population level. Effectiveness when 90% of a population is vaccinated is estimated at 85%. Two doses are required for long term prevention. The initial dose is recommended between the age of 12 and 18 months of age. The second dose is then typically given between two years and six years of age. Usage after exposure in those not already immune may be useful. Mumps vaccines are vaccines which prevent mumps. When given to a majority of the population they decrease complications at the population level. Effectiveness when 90% of a population is vaccinated is estimated at 85%. Two doses are required for long term prevention. The initial dose is recommended between the age of 12 and 18 months of age. The second dose is then typically given between two years and six years of age. Usage after exposure in those not already immune may be useful. Side effects are generally mild. It may cause mild pain and swelling at the site of injection and mild fever. More significant side effects are rare. Evidence is insufficient to link the vaccine to complications such as neurological effects. The vaccine should not be given to people who are pregnant or have very poor immune system function. Poor outcomes among children of mothers who received the vaccine during pregnancy, however, have not been documented. Even though the vaccine is developed in chicken cells, it is generally safe to give to those with egg allergies. Most of the developed world and many countries in the developing world include it in their immunization programs often in combination with measles and rubella vaccine known as MMR. A formulation with the previous three and the varicella (chickenpox) vaccine known as MMRV is also available. As of 2005 110 countries provided the vaccine as part of their immunization programs. In areas where widespread vaccination is carried out it has resulted in a more than 90% decline in rates of disease. Almost half a billion doses of one variety of the vaccine has been given. A mumps vaccine was first licensed in 1948; however, it only had short term effectiveness. Improved vaccines became commercially available in the 1960s. While the initial vaccine was Inactivated subsequent preparations are live virus that has been weakened. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. There are a number of different types in use as of 2007. The wholesale cost in the developing world of the version that includes measles and rubella is 0.24 USD per dose as of 2014. The vaccine is a component of Merck's three-virus MMR vaccine. Mumpsvax is given by a subcutaneous injection of live virus reconstituted from freeze-dried (lyophilized) vaccine. The dosage of the mumps vaccine component in MMR is the same as of Mumpsvax, 'Each 0.5 mL dose contains not less than 20,000 TCID50 (50% Tissue Culture Infective Dose) of mumps virus.' The Merck product information recommends MMR as the secondary vaccination treatment with Mumpsvax. Mumpsvax is produced from the Jeryl Lynn strain of mumps virus developed by Maurice Hilleman. When his daughter Jeryl Lynn Hilleman contracted Mumps (in 1963) Dr. Hilleman cultured the vaccine strain from her throat. The mumps virus strains were developed in embryonic hens' eggs and chick embryo cell cultures. 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. 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. Mumpsvax production as a stand-alone product ceased in 2009. Monovalent mumps vaccine (Mumpsvax) remained available in the U.S.A when MMR was introduced in the UK, replacing the MR (measles and rubella) mixed vaccine. No UK-licensed monovalent preparation was ever available. 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. 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.