The world is taking a step backwards in the fight against deadly yet preventable infectious diseases, warn experts.
The biggest global study into attitudes on immunisation suggests confidence is low in some regions.
The Wellcome Trust analysis includes responses from more than 140,000 people in over 140 countries.
The World Health Organization lists vaccine hesitancy as one of the top 10 threats to global health.
Vaccines protect billions of people around the world. They have completely got rid of one disease – smallpox – and are bringing the world close to eliminating others, such as polio.
But some other diseases, such as measles, are making a resurgence and experts say people avoiding vaccines, fuelled by fear and misinformation, is one of the main causes.
Dr Ann Lindstrand, an expert in immunisation at the WHO, said the current situation was extremely serious.