China is in a different phase where it seems they have surpressed it rather than contained it. which means if they loosen up the lock down it could revert. It’s also an economic disaster that are trying contain from all the lock down.
Yeah, if they stop containing it, it will start spreading again...
The only long term success for suppression is from a vaccine. Contained on the other hand means every infected person can gain immunity and the virus would then run out of new hosts.