MMR vaccine and autism

Two and a half years after beginning to hear evidence, the General Medical Council (GMC) has ruled that three researchers acted improperly in the conduct of their research into a proposed new syndrome of autistic enterocolitis.1 It is 12 years since publication of the study in the Lancet, which has now been retracted, described the research to which the hearing relates.2 Subsequent events have had a major impact on children’s health.

The paper described 12 children with a pervasive developmental disorder and bowel disease, which, the authors suggested, was a new syndrome. In eight of the children, symptoms were reported to have started soon after receipt of the measles, mumps, and rubella (MMR) vaccine. In their conclusions, they stated, “we did not prove an association between measles, mumps and rubella vaccine and the syndrome described” and that more research was needed. However, at a press conference, one of the authors suggested that, rather than using the combined MMR vaccine, single vaccines for measles, mumps, and rubella should be given at yearly intervals. It was this statement, unsupported by the research, that sparked media interest. At the time, the supposed link between MMR and autism was shown to be without substance,3 but it was predicted that this bad publicity could precipitate a vaccine safety scare that would result in reduced vaccine uptake and the return of measles. This has proved all too correct.

Because the media subsequently gave equal coverage to opposing views, parents understandably thought this meant that the scientific evidence for and against a link with autism was equally weighted.4 The Department of Health launched an advertising campaign; produced materials for health professionals and parents with the message that “MMR immunisation is the safest way that parents can protect their children against measles, mumps, and rubella”5; and set up a dedicated website. However, the effects of earlier health controversies such as that relating to new variant Creutzfeldt-Jakob disease had already dented public trust in the government, and the MMR controversy had all the ingredients needed for a major health scare. The vaccine is offered to every young child, but previous high vaccine rates meant that few people remembered the seriousness of measles; autism on the other hand seemed to be prevalent.

Autism is a poorly understood condition that affects social and verbal communication, one of the most fundamental human characteristics. It is therefore not surprising that public concern increased, with parents describing the decision on whether to take up the MMR as difficult and stressful.6 Parents were unsure whom to trust for impartial advice because of target payments to general practitioners6; many felt they could not get adequate answers to their questions and so turned to the internet for information, some of which was highly dubious.

Celebrities’ public declarations of their negative personal opinions about the safety of MMR only added to the interest. Parents were bombarded by conflicting, often ill informed, opinion, so they understandably felt confused and anxious. Some rejected the MMR vaccine altogether, whereas others, often the more affluent,7 sought out single vaccines on a private basis. Throughout this scare most parents continued to accept the MMR vaccine, although uptake fell from 92% in 1995-6 to 80% in 2003-4.8 This was unlike the pertussis vaccine safety scare in 1970s, when parents had a choice of vaccines with or without the whole cell pertussis component, and uptake of the pertussis vaccine fell to 31%.8 However, measles is so infectious that even a modest reduction in uptake affects disease rates. Cases of confirmed measles infection in all age groups have risen each year since 1998, with 1370 in 2008 and 1143 up to the end of November 2009. From 1995 to 2005, there were no deaths from measles, but since then there have been two in immunosuppressed teenagers.

Over time, an accumulating body of epidemiological and virological evidence failed to show any association of MMR with autism and bowel disease.9 However, restoring public confidence after such a setback is challenging and takes time; it took 15 years for pertussis vaccine rates to recover. In the case of MMR, the reduction in uptake was not so pronounced, and parents’ confidence in the vaccine recovered much quicker. This is reflected by improved uptake, with 86.5% of 2 year old children receiving the vaccine in early 2009.10 At the same time the media have made a complete about turn, with most journalists now referring to the “discredited link.”

Whatever ruling the GMC had made, it would have provided another platform for vocal anti-MMR campaigners to bring doubts about the safety of the vaccine to the forefront of the media once again, with a potential effect on a new set of parents. Although many children are not immunised because of difficulties accessing services, this can be tackled, at least in part, with accurate IT systems, reminders, and flexible immunisation services.11

The real challenge for professionals is restoring trust in parents who have decided that their children should not have the vaccine. Such parents include those of infants currently due to receive the vaccine, as well as those of the hundreds of thousands of children unprotected as a result of the scare in the early 2000s. For these parents, providing clear and accurate information on the benefits and risks of the vaccine as well as the dangers of the diseases is only part of an effective approach. The nature of the communication with parents is crucial. They are more likely to respond to a professional who listens carefully and respectfully to their individual concerns, answers their questions honestly and openly, and acknowledges when information is lacking about a particular matter.12 With this approach, and repeated opportunities to talk, parents who at first decline immunisation may be willing to reconsider.

Although responsibility for sparking this health scare must rest with the researcher who originally suggested a link, the media kept fuelling the flames. Unfortunately, at times, the response of health professionals was lukewarm, with few willing to engage in the public debate and many wavering in their support of the vaccine. If future debacles are to be prevented, professionals must enter the public arena, even though there can be unpleasant ramifications (both the authors of this editorial have received hate mail and an American researcher has even received death threats). However uncomfortable this may be, we must be firm advocates of what is best for children’s health, even if this seems to run contrary to “patient choice.”