But not all opinions are equally valid. Some opinions are wrong, and dangerously so. People put great importance on their opinions, people are stubborn. Or, alternatively, some people don't have an opinion at all. They just don't care.
A combination of people clinging to pre-formed opinions and desperately trying to rationalise them so as to sell their ignorance to others, and other people just plain not giving a toss, means that there are some places, even in the First World, where vaccination rates are not high enough. Diseases that should barely exist anymore do, because of a lack of herd immunity in populations.
It kills people. A baby in Australia, Dana Elizabeth McCaffery, would have turned one today. But not enough people in her area were vaccinated against whooping cough. She was too young to be vaccinated. She was a month old. Her parents are now fighting for the vaccination cause, and won an emotion-laden award at the Australian Skeptic's Convention last year for their bravery.
Whooping cough is not pretty; I know, I've had it, as did my brother and sister (at the same time). Fortunately, we were old enough. The coughing sounded, and felt, just awful; my mother described it as sounding like we were dying. I cannot imagine how bad it would sound when your one month old old baby girl is battling for her life in hospital.
Ignorance kills. It's that simple. When a person chooses not to receive a vaccination, they aren't just putting themselves at danger (that is their own problem). They are putting other people in danger. Listen to the doctors and the scientists when they say vaccinations work, they are professionals. Get angry at the ignorant fools who are against vaccination. Vaccination is a moral obligation.