In the UK schools have been fully open since Feb, except that bubble in schools have to isolate for 10 days if they have close contact with someone with the virus, which is pretty frustrating. This is expected to change again in August to be less restrictive, ready for school opening in September.
Starting dates vary, but generally schools will start their new school year in early September. That's when we'll really see what happens. But I'd expect most school districts to be doing full time in-person learning based on US CDC recommendations; many districts will likely make an optional online program available, but I doubt there will be many districts doing widespread online only or hybrids like we saw in the 2020-2021 school year.
I also would imagine it’s highly like the 20% of teachers not vaccinated probably had covid already…( just my guess)
1. https://www.hopkinsmedicine.org/health/conditions-and-diseas...
2. https://www.cdc.gov/media/releases/2021/s0406-teachers-staff...