Experts question latest MMR researchBMJ 2002; 325 doi: https://doi.org/10.1136/bmj.325.7360.354/a (Published 17 August 2002) Cite this as: BMJ 2002;325:354
A new US study proposing a link between the measles, mumps, and rubella (MMR) vaccine and autism in children could further inflame the controversy surrounding MMR vaccination in Britain.
The research, led by Vijendra Singh, professor of immunology research at Utah State University,was prominently covered in the Daily Mail and other British media on 9 August but received a frosty response from most British experts.
The researchers examined blood samples from 125 autistic children and 92 controls. They found an unusual MMR antibody in serum samples from 75 autistic children but not in the control samples (Journal of Biomedical Science2002;9:359-64). The authors suggested that “an inappropriate antibody response to MMR, specifically the measles component thereof, might be related to pathogen-esis of autism.”
Dr Mary Ramsay, epidemiologist at the Public Health Labor-atory Service in London, said: “We have problems with the methodology of the study. I find it a strange technique to use the vaccine as a combined antigen. The internationally validated technique is to look at these antibodies individually.”
Dr Singh's article explains his reasoning in choosing this method: “Antibodies to MMR will be atrue measure of seroconversion for this triple or polyvalent vaccine, instead of antibodies to measles, mumps or rubella viral proteins that are individually used for measuring virus serology in routine practice.”
Dr Ramsay added: “The authors report that the sera from autistic children react with one particular component of the vaccine. The evidence that this component is one particular antigen of the measles virus is not credible. Firstly, there is insufficient virus protein in the vaccine to come up positive in the type of test used by the authors. Secondly, they were unable to detect the main antigen of the measles virus (NP) while apparently detecting another antigen (HA). This doesn't hold together. If there is sufficient measles virus in the vaccine to be detected then both the NP and the HA antigens should be present.”
Dr David Elliman, consultant in community child health at St George's Hospital, London, said: “What worries me is the underlying assumptions about causality. I don't think this research moves the debate forward.”
England and Wales reported 126 measles cases this spring, compared with 32 in the last quarter of 2001.
Dr Singh was not available for comment.