reflect on this:
There was a priest in a certain town. A very devoted man, he prays and obeys God always. One day, a huge storm came and there was a flood. He prayed to God to save him. Within few minutes later, his fellow believers came to see him so that they can abandon the town as early as possible. But he said, "no I'm good. God will save me." Later, the water rose to knee-deep. The town police came to see everyone and found the priest still praying in the church. The police told the priest to come with him but the priest refused because he prayed to God and He will surely save him. Then, the water rose to his neck level. Rescuers came to save him but he still refused because God will save him. Then he died.
In heaven, he asked God why He did not save him even though he was loyal to Him and prayed to save him. But God said, "What? I sent 3 batch of people to save you but you did not go with them"
I'm not catholic, and I'm also against on some of their doctrines but I still respect them. If there is a vaccine and they choose it, then it's fine, that's free will anyway. And maybe the vaccine is the way for God to save everyone.