Had avoided Covid all 2020, but in February I needed to go to hospital for unrelated reasons -- needed urgent treatment, otherwise potentially life-threatening, had to stay several days. Had three negative Covid tests during the stay, but the fourth came back positive, just a day before my discharge. So I'm pretty sure I caught it inside the hospital. :(
My dad stayed isolated throughout 2020. He had the AZ vaccine in January. About 10 days later a blood clot to the brain caused a seizure and he went into hospital. He was tested when he went in and was not infected, he was kept fairly isolated in hospital for a couple of weeks, obviously no visitors.
We had a late night call saying he was unlikely to last the night, so we were allowed in to see him.
The next morning we were waiting for the phone call. And we had one. From Test and Fucking Trace, who wanted to speak to him. They were insistent he wasn't in hospital so we hung up on them with a rather non-polite scream.
His swab (which was from before we saw him) came back and he was positive, so we had to isolate. He did last the night, and then was moved to a covid ward.
So he clearly caught it in hospital on a non-covid ward. While I was holding his hand a nurse came along to give him an injection. She had a mask on, over her mouth - not her nose. Clearly lots of unconcious people who had frequent negative tests and weren't moving around a ward aren't going to be spreading covid, the only close contacts were the medical staff.
As it happens he lasted another 3 weeks before he came home for palative care. The vaccine presumably helped with fighting covid, but the damage caused by the siezures meant he couldn't even swallow.
He died 29 days after the positive test, so didn't go on the T+28 day stats.