Autism, inflammatory bowel disease, and MMR vaccine

Abstract

Renewed speculation surrounding the safety of MMR vaccine has followed the publication of Andrew Wakefield and colleagues'1Wakefield AJ Murch SH Anthony A et al.Ileal-lymphoid-nodular hyperplasia, nonspecific colitis, and pervasive developmental disorder in children.Lancet. 1998; 351: 637-641Summary Full Text Full Text PDF PubMed Scopus (1766) Google Scholar report of parents or physicians linking MMR vaccine with the development of autism. The Inflammatory Bowel Disease Study Group (IBDSG) has previously suggested links between exposure to wild measles virus and/or vaccine-related strains and an increased risk of developing Crohn's disease and ulcerative colitis. Evidence published in peer-reviewed journals has, however, failed to confirm a relation between measles vaccination and subsequent development of inflammatory bowel disease.2Metcalf J Is measles infection associated with Crohn's disease? The current evidence does not prove a causal link.BMJ. 1998; 316: 166Crossref PubMed Scopus (22) Google Scholar The epidemiological flaws in this latest paper concerning autism have also been well rehearsed.3Chen RT DeStefano F Vaccine adverse events: causal or coincidental?.Lancet. 1998; 351: 611-612Summary Full Text Full Text PDF PubMed Scopus (121) Google Scholar There is already evidence that current speculation has undermined confidence in the vaccine since coverage of MMR vaccine fell by 1% between the second and third quarters of 1997 across the UK. MMR coverage in Scotland has fallen to 93·7%. An increasing number of parents, according to the latest Health Education Authority tracking programme, now apparently believe that MMR vaccine poses a greater risk than wild measles virus infection.4Begg N Ramsey M White J Bozoky Z Media dents confidence in MMR vaccine.BMJ. 1998; 316: 561Crossref Scopus (57) Google Scholar The extent to which this misplaced anxiety is reinforced by professional uncertainty, indecision, and reluctance to promote vaccination has yet to be established, although we have good evidence that this was an important factor in the low uptake of measles vaccination in the 1980s.5Carter H Jones IG Measles immunisation: results of a local programme to increase vaccine uptake.BMJ. 1985; 290: 1717-1719Crossref PubMed Scopus (17) Google Scholar There is a temptation to blame the media for the drop in vaccine coverage. There is, after all, a substantial amount of evidence that contradicts the findings of the IBDSG but which tends not to achieve the same prominence in the popular press. No wonder parents are worried—they tend to hear only one side of the argument. But is it fair to blame the press? Should not the researchers shoulder the burden of responsibility? It is, after all, an awesome responsibility. It should not be forgotten that measles vaccination has substantially improved the health of children worldwide, protecting against the considerable burden of mortality and morbidity caused when the transmission of wild measles virus went unchecked. In denting parental, and possibly professional, confidence in MMR vaccination, we must not forget the consequences of wild measles virus infection, should we see its resurgence. One in 15 children would develop complications ranging from ear problems and bronchitis to pneumonia and fits. One in 5000 children would develop encephalitis and 15% of them would die. Furthermore, if the IBDSG's earlier theories have any foundation, a resurgence of wild measles virus would itself be a risk factor for the development of inflammatory bowel disease and autism. The debacle following concerns over the safety and efficacy of pertussis vaccine, based on evidence that was not later substantiated, impeded the control of whooping cough considerably in many European countries. Should we see the same situation with MMR vaccination, it would be another public health disaster. Autism, inflammatory bowel disease, and MMR vaccineAuthors’ reply Full-Text PDF Autism, inflammatory bowel disease, and MMR vaccineAuthor's reply Full-Text PDF