It’s not clear to me why China wouldn’t just get Pfizer and/or Moderna to sell white label versions of their vaccines to at least vaccinate the older population in China. And if not the US vaccines then the Oxford vaccine, which is being sold without a profit even in the West and is far superior to the Chinese equivalent, would be a cheaper option.
A big driver of the problem however is that a regime built on controlling the population will almost always default to controlling the population as the answer to its problems.
The challenge is not about getting better vaccines, but actually pushing vaccines to the older population.
For those >= 80 years old, Only 65.7% had two shots and 40% had booster [1]. This is very low compared to, for example, Singapore. [2] (>90% three shots for >= 60 y.o. group)
Chinese elders are not going to inject it into their body. You have to inject at least 3 vaccines to be sufficient against variants. The more technology advanced vaccine is going to be worse because people prefer nature herbs, further away from technology is better in their opinions.
A big driver of the problem however is that a regime built on controlling the population will almost always default to controlling the population as the answer to its problems.