FWIW - Most Chinese people are vaccinated. Gets worse when you look at 60+ and 80+ age ranges. I think your statement is still accurate though, in the sense that the lack of vaccination for the most vulnerable population may be part of the cause of Zero Covid. WaPo has a good article on this.

https://www.washingtonpost.com/world/2022/11/25/china-covid-infection-vaccines-outbreak/

"Just 40 percent of Chinese older than 80 have received a booster shot, despite months of campaigning and gift-gncourage uptake. (Among people older than 60, two-thirds have gotten a booster.)"

Restricting their vaccine from 19-60 during the early days may have created some stigma. There were also reports of blood clots for older folks, although I don't know any percentages.