Fears about the safety of the MMR jab could dramatically increase the chances of outbreaks of measles, researchers have warned.
A study has shown that even a small drop in the number of children vaccinated can greatly raise the odds of an outbreak of the potentially deadly disease.
The fear-factor effect is greatest when vaccination levels are hovering just below the target needed to keep the disease at bay in the population as a whole.
For example, the Swiss researchers calculated that if nine in ten children are vaccinated, there are unlikely to be any outbreaks of the disease.
But, if the nine in ten are vaccinated at a time when there are worries about the safety of the jab, the disease could thrive, with the number of cases similar to that expected if just seven in ten were vaccinated.
The researchers say vaccine scares can lead to clusters of unvaccinated children, making spread more likely than if the unprotected youngsters were spread evenly around the country.
