Good news. State Farm has stopped running the ad starring Rob Schneider because he has spouted anti-vaccine garbage. Sharon Hill has the story at Doubtful News.
Considering the insurance agency wants people to get vaccinated because it's good for both customers and the company's bottom line, an anti-vaxxer didn't quite fit in. Which makes you wonder whether State Farm's ad agency vetted Schneider before coming up with the lame idea to bring him back to resuscitate his only successful character, Rich The Copy Guy, in the first place.
There's a reason you haven't seen Schneider do anything since he left "SNL" -- he's not funny and never created anything else even mildly memorable.
Updated 3:21pm...Schneider is now proving that he's as uninformed about the Bill Of Rights as he is about vaccines, because he's claiming that his freedom of speech has been violated. As this post explains, he still has the freedom to say any stupid stuff he wants. The government can't stop him, but that doesn't mean there aren't consequences from other people using their free speech rights to convince a corporation (e.g. State Farm) to stop using him in their commercial campaigns.