MMR vaccine--how effective and how safe?

The introduction of combined measles, mumps and rubella (MMR) vaccine into the UK childhood immunisation schedule in 1988 has markedly reduced the incidence of these diseases and their complications, with, for example, no deaths from acute measles occurring since 1992. However, uptake of MMR vaccine has fallen since the publication, in 1998, of a study that suggested a link between exposure to the vaccine and the development of intestinal inflammation and autism. The study, and the subsequent debate, have attracted considerable media coverage and left many parents and some healthcare professionals uncertain about what to do. While in 1996, 92% of children in England and Wales had received their first dose of the vaccine by the age of 2 years, by 2001-2 this figure had fallen to 84%, with much lower uptake in some regions, threatening a resurgence of all three diseases. Here, we review the evidence for the effectiveness and safety of MMR vaccine.