Swiss parents are becoming increasingly sceptical about having their children vaccinated. Up to 20 per cent of children are no longer given shots against measles, for example, raising fears that the disease will resist efforts to wipe it out in Europe.
The recommended vaccination schedule in Switzerland and most of Europe includes shots against measles, mumps, rubella, diphtheria, tetanus, whooping cough, polio, and meningitis. And these are administered in the first 18 months of life.
Faced with this rigorous vaccination regime, many Swiss parents parents have responded by trying to limit the number of shots given to their children.
Up to 20 per cent of Swiss children are now no longer vaccinated against measles, mumps and rubella (MMR). Together with Germany, Switzerland has one of the lowest take up rates for the MMR vaccine.
What this means is that the measles virus in particular is still in circulation in Switzerland. This is a source of frustration to the World Health Organisation, which has set a target of eliminating measles in Europe by 2007.
"The problem is that here in Europe vaccination has been the victim of its own success," said John Clements of the WHO's immunisation programme. "Diseases like measles are not as common as they used to be, and young parents often don't have any experience of them, so they don't know how serious they are.
"In fact, over 800,000 children a year die from measles. In Africa you don't have to convince mothers to go ahead with vaccination, because they have seen their children die left, right and centre from the disease."
But despite the warnings, Swiss parents like Andrea Muhlherr remain unconvinced that all these vaccinations are necessary. She has five children, and has had them vaccinated only against tetanus and polio.
"The first three have already had measles," said Muhlherr. "And in autumn all five had whooping cough together. That was exhausting for me, especially at night."
But Muhlherr has no regrets about not having her children vaccinated. "I think these childhood illnesses are good," she said. "They strengthen the immune system, and children also need to learn how to be ill; to know their own strengths and to trust their own bodies."
Muhlherr was supported in her decision by her family doctor, Hans Ueli Albonico. He shares her doubts about the benefits of the MMR vaccination, and is a founding member of a working group, which calls for new and more flexible immunisation programmes.
"Vaccination can be considered a very impressive achievement," said Albonico. "But we have started asking questions about how many vaccinations are good for your child and where is the optimum level rather than the maximum."
Albonico is especially concerned about the effect of so many vaccinations so early on the development of a child's immune system.
"We have seen an explosion in the number of allergies in children from countries where the vaccination rate is high," said Albonico. "Allergies are a disorder of the immune system, so we have to ask ourselves whether there is a connection."
But the Swiss Federal Health Office takes a different view. Hans Peter Zimmermann of the immunisation programme, is keen to reassure parents who have concerns about allergies.
"There may be one or two studies which suggest a link between allergies and vaccinations," he said. "But there are also several studies which suggest vaccination may have a protective effect against allergies."
Both Zimmermann and the World Health Organisation also reject the latest study from Britain, in which research by one doctor suggested a link between the MMR vaccine and autism. The finding has caused a dramatic drop off in the number of vaccinations.
"Autism is a disease which develops in early childhood," said the WHO's John Clements. "It comes on slowly, and there may have been small signs of it prior to vaccination. But obviously if recognisable symptoms develop shortly after vaccination parents will think there is some connection.
"The problem for us is that we have to go through very complex epidemiological studies to show that there is no link between the MMR vaccine and autism. It's an uphill struggle for us sometimes."
But the continuing controversy and the conflicting evidence simply arouses more concern among many parents, who believe their best course of action is to reject a vaccination which may have unknown consequences, and take the risk of their child contracting a disease which they believe is easily treatable.
It's an attitude that paediatrician Daniel deGrandchamps, a member of Switzerland's advisory commission on vaccination, comes across daily.
"What I try to do is address the fears of the parents," said deGrandchamps. "And explain to them why, in my opinion, vaccination makes sense. It's a question of assessing the risk factors."
Degrandchamps points to a recent case in Holland, in which an outbreak of measles in a religious community of 3,000 people led to the deaths of three children. A further 17 per cent suffered serious long-term complications as a result of having contracted the disease.
"One in 2000 children contracting measles will suffer brain damage as a complication," said deGrandchamps. "It doesn't sound like a lot, until we consider that we have 2000 children here in our practice. And in comparison the risks from having the vaccination, which are so far unproven anyway, are infinitesimal."
But the fact remains that 20 per cent of Swiss parents still do not see the need for the MMR vaccine. Twelve per cent say no to whooping cough, and eight per cent to polio immunisation.
Moreover, some parents who decided against vaccination are among the most educated in Switzerland. Hans Peter Zimmermann knows that the Swiss Federal Health Office will have to work hard to convince middle class professional parents of the benefits of vaccination.
"What they need to know is that by vaccinating we prevent, every year in Switzerland, 900 cases of polio, 4,000 cases of diphtheria, or 60,000 cases of measles - and 300 deaths," said Zimmermann.
"And we don't recommend vaccines just because they are available. There is a vaccination against chicken pox now which we don't plan to recommend because chicken pox is not a disease with serious complications for children.
"Before we approve a vaccine we assess all the evidence and analyse all the risks, and if we find that the benefits of vaccinating clearly outweigh the risks, then we go ahead."
swissinfo, Imogen Foulkes