Hi Simon, welcome to the forum! I read what you said and it made me think of my friend's mum. She is 85, probably one of the fittest people I know, and smartest. I visit her, it's refreshing to talk to someone on the same wavelength.
Anyway the thing that she always says about the covid vaccine is that she lived through the polio outbreak. She says they rushed through the vaccine and offered it to key workers first, of which she was one. Fortunately she refused as there were HUGE problems and many people went down with polio and other awful side effects.
I know it's hard, I've resorted to whatsapping most of my family, then I can choose what questions to answer! Personally they should be grateful for that, the nonsense they screw out of their mouths and putting my mum in so much fear - although I warned her for years.
Anyway, maybe do some research on the polio vaccine, also you could say how there have been at least three covid trials been aborted as there have been horrendous side effects, that don't just go away, they can last for ages, if not forever.
But I know it's hardcand so draining having to explain things and defend yourself. God bless my friend, I wish you well. I also have gypsy blood in me and my daughter and I also have amazing prophetic dreams. I had a very interesting one about lockdown back in January.