MMR vaccine | Description, Age, Schedule, & Side Effects | Britannica (original) (raw)

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MMR vaccine, suspension containing live, weakened versions of the viruses that cause three diseases: mumps, measles, and rubella.

Development

The MMR vaccine was first developed in 1971 by American microbiologist Maurice Hilleman. Hilleman produced the vaccine by combining three preexisting agents. Indeed, the first vaccine against measles was licensed for use in 1963. Mass vaccination programs ensued in multiple countries worldwide, and in 1966 the first international effort focused on measles immunization emerged in Africa. Hilleman improved upon the vaccine in 1968 by generating a version that induced fewer side effects. The year before, a vaccine that he developed against mumps, which proved highly effective, had been licensed for use in the United States. In 1969, a vaccine was made available rubella. Hilleman and colleagues at Merck & Co., Inc. decided to combine the mumps, measles, and rubella vaccines as a means of simplifying vaccination schedules and thereby improving vaccine uptake.

Variants of the MMR vaccine have been developed as well. include the MR vaccine, which covers measles and rubella only, and the MMRV vaccine, which also covers varicella (chickenpox).

In the United States, MMR vaccine is given in two doses: the first to infants at 12 to 15 months of age and the second to children between ages four and six years. In other countries, the vaccine is given first at nine months and the second dose later. In all dose schedules, the second dose must be given at least four weeks after the first dose.

The youngest age at which the vaccines can be given is six months, though revaccination (with two doses) is needed later. Vaccination is not recommended for pregnant women. MMR vaccination may be accompanied by mild joint pain and fever in a small number of individuals; more severe side effects, such as anaphylaxis, are uncommon.

The Editors of Encyclopaedia BritannicaThis article was most recently revised and updated by Kara Rogers.