When I think of convincing, I think of proselyting. It's a terrible way to get people to do what you want them and all the censoring and coercion tv. seems like people are drawn in hook, line, and sinker.
When it comes to one's health, I think a lot of people are less resilient to take people's advice other than doctors (their doctors) and maybe family. I guess the best scenario I can think of is like being in a dangerous neighborhood X and most people carry guns except a few minority who choose not to. Then when people are killed because of crime, the people with guns (to protect) blame the death of the victims on those who choose not to protect themselves and thereby others.
If the neighborhood had intense crime, I can kind a see it. If the crime rate is low, people can carry guns just in case but to belittle those who choose not to, that's an issue-I have.
I use analogizes cause I can make points better.
I wouldn't try to convince your friend. Instead, just be a friend. My friend took the vaccine and her children will when they quisi approve it for children or they reach of age. I'm not angry at her, tell her she's wrong, or anything like that "and" she doesn't tell me likewise. I'm glad she made a decision best for her and her children's well-being. Many of those who aren't unvaccinated are not at a high danger to someone to possibly spread the virus (asymptomatic or not). So, it really depends on the person. Maybe your friend has a valid reason and maybe you just don't accept that reason? I don't know.