Sounds like my own mother. I recently sent her
this excellent video (in Spanish) which explains the current covid vaccines and their dangers in detail. It's full of facts, it's very rational, and it comes from an actual no-nonsense scientist. She watched it and commented it was very interesting. A few days later, she announced she just got the first shot of the Pfizer vaccine. My brothers, who didn't bother to watch the video I sent them as well, cheer. One of them said he and his wife rushed to the US to get their first shot as well (not available for his age group in my country yet), and that the Pfizer so-called vaccine is the best one.
Since then, I make an effort to avoid the subject, since my mother has already made her choice and I had already repeatedly said what I thought about it, so by now it's totally pointless. But in conversation someone mentions the case of an elderly man who got very ill after taken the vaccine. My mom comments it's probably just a coincidence. Yet she has also commented on cases of people who had covid, recovered and a couple of months later got complications from something else and died, that it was a 'covid sequel'. No coincidence there. Because, like you say, Official Culture. She watched it on TV, so it must be true. What Officialdom says has more weight than fact-based arguments.
Luckily, no one in my family who's had the vaccine has had any adverse reaction yet. But who is to tell what will happen when their immune systems react to a real virus, or what autoimmune conditions or cancer or whatever await down the road?
Ultimately, I think it's about free will and personal lessons. You can't force anyone into anything good, and our own lesson is to accept that.