A combined vaccine offering protection against MEASLES, MUMPS and RUBELLA (German measles), it was introduced in the UK in 1988 to replace measles vaccine. The combined vaccine is offered to all infants at 13 months and repeated with the pre-school booster doses against DIPHTHERIA, TETANUS and POLIOMYELITIS. MMR vaccine may also be used in the control of measles outbreaks, if offered to susceptible children within three days of exposure to infection. The vaccine is effective and generally safe, though minor symptoms such as malaise, fever and rash may occur 5–10 days after immunisation. The incidence of all three diseases has dropped substantially since MMR was introduced in the UK and US.