You literally can. It is not particularly easy, but it is possible. It's just not something vaccines alone can do. And masks, while helpful, are probably not enough either.
Are you really that unfamiliar with the concepts of both immunity and mutation? A demand for data to support the conclusion that a virus changing is likely to make existing immunities-- based on previous iterations of the virus-- less effective is, frankly, bizarre. I'm not saying such data doesn't exist, but the conclusion you're asking me to show evidence for is so uncontroversial that I am not going to bother finding it for you; what I wrote is true not just about COVID and vaccines or natural immunities (as disappointing as both already are in the case of COVID-19), but about literally any virus.
When someone is infected with a virus, that virus replicates. A lot. And sometimes it replicates imperfectly. And those imperfections that will tend to be replicated more are ones that make it more likely to spread because that's just how natural selection works.
They've proven that it is quite possible to stop the spread of the disease. But, largely because other places are not taking similarly effective measures, the disease still exists to be constantly reintroduced back to their society by the rest of us. There should be a global effort to isolate and eradicate the disease. I'd say we have a lot to learn from China, but it's not a lack of knowledge that we have. It's a lack of a politics that values human life. I expect whatever you've read about China's difficulties is exaggerated because capitalist media has an interest in maintaining the status quo of people going to work and making money for their employers; COVID measures would disrupt that-- they might even require government spending or methods of economic organization that (quelle horreur) do not rely on private owners and the market. Not even the fact that constantly getting COVID means constantly suffering risks of long COVID symptoms, all the worse with repeated exposure, is enough to shake sense into us.