Even if you're not concerned for your own safety but you live with older people, you still might want to wear an elastomeric respirator or DIY PAPR when going out in order to protect them and encourage them to do the same.
Don't poz yourself, China is the only country in the world where you aren't virtually guaranteed to get infected (although this may change). There is brain damage at stake. I don't know how dangerous the current strain is, since most people in China have little herd immunity (and Sinovac's contribution is unclear) and hospitals might be overrun.
In the US, the standard is P-100 masks which were recommended for SARS in 2014. You can get them at the hardware/construction store and they look like this (they are not electric and cost $10-15 at the hardware store in the US, probably more like $200 in China if they're in stock at all, but one mask will last >6 months):


N95 and KN95 masks probably don't work very well.
If you're in an apartment, seal off the ventilation system by covering it up with a layer of Duct Tape, and use windows and a plug-in heater instead. If you share a door with a hallway, attach a fan to your window and have it blow air in whenever you open or close that door so that the hallway air does not enter.
Lastly, this is things you can do for people who get covid, yourself and others. I have no idea how many of these are available inside China, but the list is ordered properly.
Possible to stock up on antiviral drugs instead?
So, uh, things in China are getting a bit interesting.
There's a general consensus that the public COVID numbers no longer reflect reality. Baidu started hiding their case tracking display. Their last updates had weird inconsistencies between asymptomatic and symptomatic cases. Testing stations are going offline. While previously a single case of close contact would have been enough to shut down an entire college, now facilities are running even with multiple symptomatic cases. Every time things have loosened to this degree before, cases have spiked. Many people I know mentioned family members being infected, some of which are unreported, while official case numbers are on the decline. The security people who checked health app codes aren't even pretending to care anymore. I was explicitly told not to show them my health codes when I come to work today. Lines for testing booths at peak times are basically non-existent.
I think this is it. COVID will go full endemic in China. Exponential.
I'm in my late 20s and in great physical condition. I exercise multiple times a week (weightlifting only). Unfortunately, I only have 2 shots of Sinovac. I'm planning to get some dental work taken care of this weekend and will get a third shot if it's available.
I think I have 2 options, really. First, I fly to Hong Kong and get the mRNA vax there, which an executive at my company mentioned she planned to do. Not sure if the EV is going to be positive, and I'll have to take a week off work. Second, I go to a hospital/visit a poz family friend and intentionally poz myself ASAP before the hospitals get overloaded.
Overall, I'm not too concerned, but am interested in what you guys think. I would also love to hear any investment advice from those familiar with Chinese markets.