So far, most of these studies have mostly been on vaccinated populations, e.g., enrollment in https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0290893 was 20/05 to 21/12 and vaccines started becoming generally available in 21/08, so the population is likely to mostly be vaccinated people.

There's at least one cohort for which people have published longitudinal data on cumulative impact (and it doesn't look good), but there's a lot of heterogeneity between populations and it would be nice to see more data on this.