Two-part question

No, I'm afraid you need to go through the security check again in Beijing airport.
Any kind of covid test is not required any more; it has been the history.

Thank you. I meant once I am through security. I know I have to go through once, when I arrive from ICN, but what about before I catch my next flight. Do I have to, for instance, go through security again if I want to go from 3C to 3E?
Thanks also for the good news about the COVID situation.

It depends on if your flight is a connecting flight. If it is, then you don't need to go through the security again. Just confirm it with your air company.

Thank you Andy - yes I am transiting. In my case, my flight from ICN lands at 3C and I go through security. I then have a long layover (5 hours). During that time, I want to go to 3E to spend some time in an airport lounge to which I have access before heading back to 3C to catch my international flight out.
Do you know if that is that possible without going through security again? Thanks again.

It's possible. Wish you a smooth trip~

Thank you Andy for your kind reply and for the good news too. Sometimes at PEK the security/passport check lines are long and I only want to do it once. I hope to get to the Air China first class loungein T3E, as it looks like the nicest one. Happy trails to you too.