I don't know why you're getting some of these snotty replies. Ours are 4 and 2. Incredibly healthy (get that from DH not me) - 4 yo has had one antibiotic ever, 2yo only ever been at GP for immunisations.
Sept to Dec I think DH and I both worked five days in a week once, maybe twice. I remember us celebrating. Every cough or temperature meant a PCR and isolation so that was at least one day off to get tested and plans cancelled if it was the weekend. That's not our nursery being strict that's just what all of us were supposed to be doing at that time.
4yo got a high temp on the evening of 23 Dec, meaning Christmas plans were rearranged for multiple households until the 24 Dec PCR result came through on Christmas morning and we could host as originally planned.
Jan-March weren't too bad, although the only vomiting bug coincided with our first night out to an event in 4 years so that was cancelled.
April we all got covid and that killed plans for Easter, DD1's birthday and my first solo night away in two years.
May DD1 got chickenpox.
June DD1 got croup (at 4! Taking the piss now surely), then they both got a tummy bug that meant I had to cancel a couple of nights away to meet my newborn niece.
1 July DD1 started new childcare provision and threw up on day 1. So they'll love us.
It's fucking relentless. I'm up at this hour with snotty, coughing DD2 who can't settle. Will need to LFT her in the morning but hopefully she'll be ok for nursery.
I don't remember it being anywhere near as bad with dd1 pre covid, and that was the traditionally bad first winter at nursery.