“Many people fear vaccines. The immense progress made by vaccines in terms of eliminating or strongly reducing vaccine-preventable diseases such as measles or polio have made them a victim of their own success. Newer generations of parents do not see the benefit, because you do not see anything when vaccines work.
Then they might be more trusting of conspiracy theories they find on social media websites such as Youtube than what they find on the CDC or WHO websites. As a result, we have now begun to see the return of some vaccine-preventable diseases such as pertussis and measles. Efforts to eliminate polio and measles across the world are stifled by anti-vaccine sentiments.”