More than a decade ago, British parents refused to give measles shots to at least a million children because of a vaccine scare that raised the specter of autism. Now, health officials are scrambling to catch up and stop a growing epidemic of the highly contagious measles virus.

This year, the U.K. has had more than 1,200 cases of measles, after a record number of nearly 2,000 cases last year. The country once recorded only several dozen cases every year. It now ranks second in Europe, behind only Romania.

Last month, emergency vaccination clinics were held every weekend in Wales, the epicenter of the outbreak. Immunization drives have also started elsewhere in the country, with officials aiming to reach 1 million children aged 10 to 16.

"This is the legacy of the Wakefield scare," said Dr. David Elliman, spokesman for the Royal College of Paediatrics and Child Health. He’s referring to a study published in 1998 by Andrew Wakefield and colleagues.

That work suggested a link between autism and the combined childhood vaccine for measles, mumps and rubella, called the MMR vaccine.

Several large scientific studies failed to find any connection, the theory was rejected by at least a dozen major U.K. medical groups and the paper was eventually retracted by the journal that published it.

Britain's top medical board stripped Wakefield of the right to practice medicine in the U.K., ruling that he and two of his colleagues showed a "callous disregard" for the children in the study. Wakefield took blood samples from children at his son's birthday party, paying them about 5 pounds each ($7.60) and later joked about the incident.

Still, MMR immunization rates plummeted across the U.K. as fearful parents abandoned the vaccine — from rates of over 90 percent to 54 percent. Wakefield has won support from parents suspicious of vaccines, including Hollywood celebrities like Jenny McCarthy, who has an autistic son.

Nearly 15 years later, the rumors about MMR are still having an impact. Now there's "this group of older children who have never been immunized who are a large pool of infections," Elliman said.

The majority of those getting sick in the U.K. — including a significant number of older children and teens — had never been vaccinated. Almost 20 of the more than 100 seriously ill children have been hospitalized and 15 have suffered complications including pneumonia and meningitis. One adult with measles has died, though it's unclear if it was the infection that killed him.

The first measles vaccines were introduced in the 1960s. They dramatically cut cases of the virus, which causes a distinctive rash. Since 2001, measles deaths have dropped by about 70 percent worldwide; Cambodia recently went more than a year without a single case.

Globally, though, measles is still one of the leading causes of death in children under 5 and kills more than 150,000 people every year, mostly in developing countries. Measles is highly contagious and is spread by coughing, sneezing and close personal contact with infected people; symptoms include a fever, cough, and a rash on the face.

Across the U.K., about 90 percent of children under 5 are vaccinated against measles and have received the necessary two doses of the vaccine. But among children now aged 10 to 16, the vaccination rate is slightly below 50 percent in some regions.

To stop measles outbreaks, more than 95 percent of children need to be fully immunized. In some parts of the U.K., the rate is still below 80 percent.

Unlike in the United States, where most states require children to be vaccinated against measles before starting school, no such regulations exist in Britain. Parents are advised to have their children immunized, but Britain's Department of Health said it had no plans to consider introducing mandatory vaccination.

Last year, there were 55 reported cases of measles in the United States, where the measles vaccination rate is above 90 percent. So far this year, there have been 22 cases, including three that were traced to Britain. In previous years, the U.K. has sometimes exported more cases of measles to the U.S. than some countries in Africa.

Portia Ncube, a health worker at an East London clinic, said the struggle to convince parents to get the MMR shot is being helped by the measles epidemic in Wales.

"They see what's happening in Wales, so some of them are now sensible enough to come in and get their children vaccinated," she said.

Clinic patient Ellen Christensen, mother of an infant son, acknowledged she had previously had some "irrational qualms" about the MMR vaccine.

"But after reading more about it, I know now that immunization is not only good for your own child, it's good for everyone," she said.

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By Rachael Rettner
MyHealthNewsDaily

The number of measles cases and outbreaks spiked last year, with unvaccinated people making up the majority of those affected, according to a new report from the Centers for Disease Control and Prevention.

In 2011, there were 222 cases of measles in the United States. That's the highest number reported measles cases in the united states in 15 years, said Dr. Anne Schuchat, director of CDC's Office of Infectious Diseases, speaking to reporters today.

The number is also more than triple the number of cases in 2009 and 2010, according to the report.

About half of the 2011 cases occurred during outbreaks, which are defined as at least three cases that are linked to each other. Last year, there were 17 measles outbreaks, well above the average of four for the previous decade.

Among patients who were U.S. residents, 72 percent of cases developed in people who had not received the measles vaccination, or had unknown vaccination history, despite being eligible for the vaccine. (Twenty-six cases occurred in people living outside the U.S.)

Fifty patients were children between 16 months and 19 years old who had not been vaccinated for philosophic or religious reasons or personal objections, the report says.

Since 2000, measles has been considered eliminated in the United States. The disease occurs here mostly when people become infected after traveling to other countries and transmit the disease to others upon their return. Indeed, 90 percent of the cases in 2011 had their origins in other countries, including 52 U.S. citizens who became ill after traveling abroad.

"The increase in measles importations and outbreaks during 2011 serves as a reminder that measles remains endemic in many parts of the world and unvaccinated U.S. residents continue to place themselves and others in their communities at risk for measles and its complications," the report says.

In 2011, more than 30,000 cases of measles were reported in European countries, with France, Italy, Romania, Spain and Germany having the majority of cases.

The measles, mumps and rubella vaccine is recommended for all children ages 12 to 15 months, with a booster shot at age 4 to 6 years. Children as young as 6 months can recieve the vaccine if there are plans for the family to travel abraod. Adults should be vaccinated if they did not recieve the vaccine when they were younger.

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By Rachael Rettner
MyHealthNewsDaily

Tim Boyle / Getty Images file

As cases of a disease decrease, people can start believing the risk from the vaccine is more than the threat of disease.

Vaccine scares, which lead portions of the population to forgo vaccination, could become more common as more diseases are eradicated, researchers say.

That's because, as cases of a disease decrease, people become complacent about their risk, and the threat of vaccines — whether imagined or real — seems greater than the threat of disease, said Chris Bauch, a professor in the department of mathematics and statistics at the University of Guelph in Ontario.

"High vaccine coverage is inherently unstable," Bauch said. Unless vaccination is mandatory, "I think we'll see more of this problem in the future," he said, referring to vaccine scares.

Vaccine scares are a problem because, when vaccination rates drop, preventable diseases such as measles and whooping cough can make a comeback. However, there may be ways to soften the blow of these scares.

Bauch and colleagues have constructed a mathematical model to predict the course of vaccine scares, including when they will peak and how long they will last.

Such models could one day be used to test the effectiveness of public health campaigns that aim to increase vaccination rates, Bauch said. For instance, the model could determine what type of campaign will work best: one that emphasizes the safety of the vaccine, or the danger of the disease, Bauch said.

To test their model, Bauch and colleagues used real data from two vaccine scares in the United Kingdom — the whooping cough vaccine scare in the 1970s and the measles-mumps-rubella (MMR) vaccine scare in the 1990s.

The researchers found their model could explain the rise and fall of vaccine coverage, and could also predict the vaccine scare outcomes.

One factor crucial to the success of the model was the inclusion of social learning, meaning the way in which people learn vaccinating behaviors from one another, Bauch said.

The model explained why it took four to five years after the start of the vaccine scares for vaccine coverage to reach its minimum. If threat of disease and the perceived threat of vaccines were the only factors that played into vaccination rates, one would expect vaccine coverage to dip significantly after people heard news reports questioning the safety of the vaccines.

However, because social learning plays a role, this was not the case. Declines in vaccine coverage take time because non-vaccinating behaviors have to "spread" from parent to parent, Bauch said.

The study will be published in the April issue of the journal PLoS Computational Biology.

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