ROCHESTER, Minn. -- More than 150 cases of measles have been reported in the United States already this year and there have been similar outbreaks in Europe, a sign the disease is making an alarming comeback. The reappearance of the potentially deadly virus is the result of unfounded fears about a link between the measles shot and autism that have turned some parents against childhood vaccination, says Gregory Poland, M.D. (http://www. mayoclinic. org/ bio/ 10966366. html ), of Mayo Clinic. In the September issue of Mayo Clinic Proceedings (http://www. mayoclinicproceedings. com ), Dr. Poland urges doctors to review extensive scientific research that has found no connection between the measles-mumps-rubella (MMR) vaccine and autism.

Fears about the MMR vaccine were sparked in 1998 by researcher Andrew Wakefield, M.D., in the British medical journal The Lancet (http://www. sciencedirect. com/ science/ journal/ 01406736 ). Dr. Wakefield's study was later found fraudulent by the British General Medical Council and the paper was retracted. Even so, suspicions about the vaccine -- as well as its additives such as thimerosal -- have persisted, gaining steam with the public through celebrity advocates and widespread media coverage.

"A rising portion of the population is deciding not to immunize their children because of this controversy, and these children are now susceptible to the measles (http://www. mayoclinic. com/ health/ measles/ DS00331 ) virus," says Dr. Poland, Mary Lowell Leary Professor of Medicine and director of the Mayo Clinic Vaccine Research Group.

"The results have been devastating," Dr. Poland says. "The campaign against the vaccine has caused great harm to public health across multiple nations, even though it has no scientific basis. There have been over 20 studies, spanning two decades, conducted in several countries. Not one has found scientific evidence of a connection between autism spectrum disorders and MMR vaccine."

Measles remains the most contagious infectious disease humans can get. It kills roughly three of every thousand people infected. Due to the vaccine's effectiveness and successful immunization programs worldwide, indigenous cases of the disease had been eliminated in the U.S. and on track to be eradicated, similar to smallpox.

Dr. Poland recommends that doctors, patients, and the media become educated about the research on the research that already has been conducted and help rectify the misinformation. A major report released by the Institute of Medicine last week supports Dr. Poland's claims of no connection between the MMR vaccine and autism (http://www. mayoclinic. com/ health/ autism/ DS00348/ DSECTION= causes ).

"Just as significantly," he adds, "we need to direct appropriate and significant funds to determine what's really causing autism in our children."

###

A peer-reviewed journal, Mayo Clinic Proceedings publishes original articles and reviews dealing with clinical and laboratory medicine, clinical research, basic science research and clinical epidemiology. Mayo Clinic Proceedings is published monthly by Mayo Foundation for Medical Education and Research as part of its commitment to the medical education of physicians. The journal has been published for more than 80 years and has a circulation of 130,000 nationally and internationally. Articles are available online at www.mayoclinicproceedings.com.

About Mayo Clinic

Mayo Clinic is a nonprofit worldwide leader in medical care, research and education for people from all walks of life. For more information, visit www.mayoclinic.org/about.