MMR scare separates the educated affluent from the poor

The scare over a possible association between the triple measles, mumps and rubella vaccine (MMR) and disorders such as autism and inflammatory bowel disease led to a troubling decline in uptake in the UK during the 1990s.

From 92 per cent in 1995 it fell back to 79 per cent in 2003, rising thereafter to 85 per cent in 2007. And, in line with these fluctuations, rates of confirmed measles cases increased from fewer than 100 in 1998 to almost 1,000 in 2007.

The combination of these trends, which included a fashion for single antigen vaccination as a “safer” choice, as well to a rise in numbers of parents failing to vaccinate their children altogether, had the spin-off benefit of creating a pool of public health trend data about parenting behavior.

Anna Pearce and colleagues at the Institute of Child Health [1] have sifted information about 14,578 children in the UK Millennium Cohort [2] to assess their immunization status in relation to such factors as geographic location, socio-economic status, cultural risk factors and parent attitudes towards immunization.

With future public health strategies in mind, they have distinguished two groups – those who actively chose not to immunize their children and others who made no such active decision, but whose children were nevertheless not fully immunized.

Parents who made a conscious decision not to use the MMR vaccine were more likely to be white, well educated, affluent older mothers with one child. Three quarters of parents not using the MMR made a conscious decision and they were also more likely to vaccinate their children using single antigen vaccines.

The remaining quarter of parents who declined MMR were more likely to have children who were only partially vaccinated or not vaccinated at all and more likely also to display indicators of lower socio-economic status.

While not surprising, bearing in mind the characteristics of the anxieties about MMR, the Institute's findings should prove useful when considering population-wide strategies for improving rates of immunization and for designing targeted services. (The goal of the UK health service is to reach a 95 per cent coverage; 85 per cent uptake leaves a substantial proportion susceptible to avoidable infections.)

The team conclude that families who selectively refuse MMR are more likely to be respond to education campaigns improving understanding of the safety of the MMR. Parents from lower socio-economic groups may benefit from legislation designed to provide incentives, such as financial enticements or eligibility for childcare provision as well as appointment reminders and increasing access to the vaccine.

These approaches have previously been found to improve immunization coverage, but Paul McIntyre, editor of the influential British Medical Journal, believes they require greater legislative action and societal support.

• The report by Anna Pearce and colleagues is available online from the British Medical Journal as Factors associated with uptake of measles, mumps, and rubella vaccine (MMR) and use of single antigen vaccines in a contemporary UK cohort: prospective cohort study [3].