The impact of the media on the decision of parents in South Wales to accept measles-mumps-rubella (MMR) immunization

A large measles outbreak occurred in South Wales in 2012/2013. The outbreak has been attributed to low take-up of measles-mumps-rubella (MMR) immunization in the early 2000s. To understand better the factors that led to this outbreak we present the findings of a case-control study carried out in the outbreak area in 2001 to investigate parents' decision on whether to accept MMR. Parents who decided not to take-up MMR at the time were more likely to be older and better educated, more likely to report being influenced by newspapers [adjusted odds ratio (aOR) 3.07, 95% confidence interval (CI) 1.62-5.80], television (aOR 3.30, 95% CI 1.70-6.43), the internet (aOR 7.23, 3.26-16.06) and vaccine pressure groups (aOR 5.20, 95% CI 2.22-12.16), and less likely to be influenced by a health visitor (aOR 0.30, 95% CI 0.16-0.57). In this area of Wales, daily English-language regional newspapers, UK news programmes and the internet appeared to have a powerful negative influence. We consider the relevance of these findings to the epidemiology of the outbreak and the subsequent public health response.