Britain is experiencing serious outbreaks of measles that look to be a delayed consequence of a failure to vaccinate infants and young children more than a decade ago. A prime cause of that failure was ill-founded fears among parents that a widely used vaccine to combat measles, mumps and rubella might cause autism. Because they shunned the vaccine, their children, now in their teens, are suffering the consequences.

Those fears had been fanned by Dr. Andrew Wakefield, a British researcher, who claimed to have found a link between the vaccine, gastrointestinal problems found in many autistic children and autism itself. His work was subsequently discredited, and the BMJ, a British medical journal, concluded that flaws in his scientific study were not honest mistakes but an “elaborate fraud.”

Even so, he has stalwart defenders who ignore the overwhelming consensus of vaccine and infectious disease experts that the vaccine is safe and effective and not a cause of autism. It has a proven record of safety when given to hundreds of millions of people around the world.

Last year, Britain had some 2,000 reported cases of measles, and it has already had more than 1,200 this year. The highest rates are among adolescents who were never vaccinated, some because they lacked easy access to vaccines, others because their parents feared autism. The most serious outbreaks this year have been in Wales, where there are also signs that mumps may be increasing. A vaccination campaign aimed mostly at young people ages 10 to 16 is now trying to fill a gap that should never have occurred.