By Kate Kelland

Public confidence in immunization varies widely across the world with the French the most skeptical about the safety of vaccines, according to a survey published on Friday.

With outbreaks of measles, whooping cough and other infectious diseases occurring in recent years in places where the take-up of vaccinations has been low, the scientists behind the survey said its insights could help policymakers tackle such problems.

The study took views from almost 66,000 people across 67 countries about whether they consider vaccines important, safe, effective and compatible with their religious beliefs.

France - the birthplace of immunology pioneer Louis Pasteur - was the country least confident of vaccine safety, with 41 percent of those surveyed disagreeing that vaccines are safe, more than three times the global average of 12 percent.

Europe had six other countries among the 10 least trusting - Bosnia & Herzegovina, Russia, Ukraine, Greece, Armenia and Slovenia.

Publishing their findings in the journal EBioMedicine, researchers led by Heidi Larson of the Vaccine Confidence Project at the London School of Hygiene & Tropical Medicine said negative attitudes may be due to controversies over suspected side-effects and hesitancy among some family doctors.

Public trust in immunization is an important global health issue, with lack of trust leading people to turn down potentially life-saving vaccines.

Vaccine refusal has been linked to outbreaks of diseases such as measles in the United States, Europe, Asia, the Pacific and Africa in recent years, and has also caused serious setbacks to global ambitions to eradicate polio.

"It is vital to global public health that we regularly monitor attitudes towards vaccines so we can quickly identify countries or groups with declining confidence," Larson said. "This gives us the best chance of preventing possible outbreaks of diseases."

The survey found southeast Asia was most confident in safety, with fewer that 1 percent in Bangladesh thinking vaccines were not safe.

It also found that some countries including France had much greater confidence in the importance of vaccines than in their safety.

"This ...shows that vaccine acceptance is precarious," said Larson, adding that scientists and public health authorities need to "do much better at building public trust".