In Europe, most people follow the recommended vaccination schedules. But outbreaks of measles, pertussis, rubella and other vaccine-preventable diseases continue.
This is because almost everyone needs to be immunised in order to control the spread of these highly infectious diseases, and protect those who are too sick to be vaccinated.
Take measles, for example. For measles to be eliminated, 95% of children must have two doses of the MMR vaccine.
This means that even if most people are vaccinated, the disease can persist in the community if the target vaccination rate of 95% is not reached.
We took to the streets to ask members of the public for their views on immunisation and what influences the decision to vaccinate.
