One possibility is that the Chinese plan is for the next virus to target only those who have received the mRNA vaccines. That would be 85% of Americans and about 0% of Chinese.
I would assess that possibility as "almost certainly true".
But the Chinese do not understand what they are doing. Nobody really does understand the subtleties of viral DNA and RNA interactions with human or animal tissues. The Chinese will attempt a large number of experiments and those will not work in the manner they expect. The consequences will be far worse than what they are prepared to deal.
The Chinese authoritarian system and bureaucracy creates enormous pressure to produce "results" and equally enormous pressure to falsify "results". They also cover up terrible mistakes to a degree far outside our experience. They are going to make terrible mistakes and then deny them in great detail. It won't matter. Some mistakes are unrecoverable and end the lives of those who make them, regardless of how well they cover up their actions.
The survivors will deal with the consequences.