You can't dis-empower the anti-vaxers. You are bound to the truth and they are not. Everything you say, including nothing, is affirmation of the conspiracy against them.
The best you can do is handle the situation as best you know how, including changing your mind. And your messaging, as you come to understand how it works, knowing full well how the conspiracy theorists will portray each change you make.
They are a deadweight loss. You won't beat them. You have to fight the disease instead, knowing that there is an enormous force out there making your insanely difficult job even harder. Time spent appeasing them is time lost.
Indeed - the entire process of developing the vaccine in a timeline branded 'warp speed', relying on it as the only means to avoid lockdowns (which have never been based in anything resembling science), indemnifying the organizations who stand to profit from it, and now perhaps exacting pressure on the public to accept it - these steps all seem tailor-made to strengthen the antivax movement. It's terrifying.
mRNA is rad technology. It will be a major bummer if it gets derailed because of these blunders.
They already don’t trust you, how do you think you changing definitions like this is going to accomplish.