Support worker is a pandemic denier

I am struggling with how to approach re-evaluating my established support worker, after latterly discovering that he denies that we are in a pandemic. I am hoping for some guidance.
I get funding for a support worker to help push me out of my inertia and isolation due to mental health issues. I have trouble communicating with people and engaging with them in general, so finding a support worker who was generally supportive and friendly was a win. He is a mostly open minded person trained as a yoga instructor. However, the online yoga community is apparently over-represented in the social media bubble of Covid disinformation.
When he declared that he had a medical exemption from wearing a face covering I took him at his word and let it slide. When I later mentioned my two Astra Zeneca vaccination doses, he began offering me disinformation-type claims - indicating that my taking on an untried experimental treatment pushed by a corrupt pharmaceutical industry is making me culpable for side effects that I might pass to him and others. All in response to a disease that is supposedly no worse than a cold, and not a real pandemic. (As opposed, to say, acknowledging that staying unvaccinated and potentially incubating more covid variants makes abstainers like him concretely responsible for keeping the wider population from ever reaching herd immunity. )
I started getting into a heated riposte trying to get him to see the unscientific nonsense and irrational fallacies I saw in his words. But I knew that was going to just erase any goodwill we had.
I said that I needed to prepare an exercise we could work through together, to identify where he and I might be willing to adjust and compromise and where we each could not. I scheduled it for later this week. But I don't know that I have a way to do that that is not going to just fall over if it becomes clear we do not exist in the same consensus reality, and what counts to me as threatening risks to the community is just illusory propagandised fears to him.
I dug up some old support group literature about communication skills and mediation, but I don't really know how to apply the ideas in them.