The person I believe is the loudest voice against vaccines is Alex Jones. He has a large audience.
While I don't believe vaccines are without risk, on balance, many are statistically better than not.
Alex means well concerning this issue. He just thinks pharmaceutical companies are too much the crony capitalists where Alex is more libertarian and definitely anti-cronyism.
Big Pharma, as it is called, does have a history of putting money and profits ahead of people's health. People, such as Mike Papantonio (a certified progressive, certainly not in Alex Jones' libertarian-capitalist camp), have done a great job voicing concern about the misdeeds of major pharmaceutical companies.
"Papantonio: Ripped Off and Murdered By Big Pharma":
"Papantonio: Dysfunctional FDA in Big Pharma's Pocket":
It is a mistake to fall completely on one side or the other of this issue. Not all vaccines are bad by any stretch. Likewise, not all vaccines are good. Plenty of "medicines" should never have been released. Many have been withdrawn.
So, we must find the truth and the right balance of risk. We aren't even close to doing that right now.
The loudest people are either completely opposed to all vaccines or have their heads buried in the ground about the terrible things that have happened to people as a direct result of consuming or being injected with extremely dangerous and harmful "medicines."