RE: 'ER Uproar' (February 23, 2001)
To the Editors:
Because only the views of the autism community were represented in the on-line story "ER Uproar," readers might be left with the impression that a link between vaccination and autism is an accepted truism.
We would like to balance that viewpoint by providing a medical perspective on the issue.
The results of many well-designed, well-conducted studies have shown no association between use of the MMR vaccine and the development of autism. The small study that first proposed this hypothesis has not been replicated by any other researchers.
An extensive review of this hypothesis conducted by the American Academy of Pediatrics will be published in the coming months, but the interim report from the Executive Committee states, "The bottom line is that a considerable body of evidence does not support a causal relationship between MMR vaccine and autism or inflammatory bowel disease. No data exist to suggest that separate administration of measles, mumps and rubella vaccines would offer any potential benefit over the MMR vaccine currently used in the United States. Furthermore, there is ample reason for concern that such an approach would result in many underimmunized children."
While additional studies underway will continue to explore this issue, the overwhelming majority of the studies published to date fail to show a causal relationship between the MMR vaccine and the occurrence of autism. For example, a study in this week's Journal of the American Medical Association (March 7, 2001) showed no correlation between the dramatic increase in the number of children diagnosed with autism in California and the proportion of children over that same period who received the MMR vaccine(1). Once again, the best available science has shown - consistently - that there is no association between vaccines and autism.
On the other hand, we know with absolute certainty that unvaccinated children are many times more likely than their vaccinated neighbors to contract a serious infectious disease, suffer long-term consequences of that disease, and, potentially, die from the disease. Two recent studies found that unvaccinated children are 22-35 times more likely to contract measles (2,3) than unvaccinated children are.
Fortunately, we live in a country and at a period in history when a child dying from measles is an anomaly. We have the luxury of debating whether the tragedy depicted on "ER" is an appropriate representation of reality. But just a decade ago, when vaccination rates fell, we saw over 55,000 cases of measles in the U.S. (mainly in children less than five years of age), more than 11,000 hospitalizations, and 125 deaths. Because of increased vaccination rates, there were fewer than 100 cases in each of the last three years.
Every vaccine - in fact, every medical procedure - has some risk associated with it. However, the risk of an adverse event from a vaccine is miniscule when compared with the odds that a child who isn't vaccinated could be seriously harmed by an infectious disease. Moreover, simply because we exist in a time and a place when we rarely see these diseases, we cannot allow ourselves to be lulled into thinking that the decision not to vaccinate is a decision that is risk-free.
Bruce G. Gellin, M.D., MPH
National Network for Immunization Information
Department of Preventive Medicine
Vanderbilt University School of Medicine
1. Dales L, Hammer SJ, Smith NJ. Time Trends in Autism and in MMR Immunization Coverage in California. JAMA, 2001; 285: 1183-1185.
2. Feikin DR, Lezotte DC, Hamman EF, et al. Individual and Community Risks of Measles and Pertussis Associated with Person Exemptions to Immunization. JAMA, 2000; 284:3145-3150.
3. Salmon DA, Haber M, Gangarosa EJ, et al. Health Consequences of Religious and Philosophical Exemptions From Immunization Laws: Individual and Societal Risk of Measles. JAMA, 1999; 282:47-53.