O is supposedly safe.
This has been discussed before, but not necessarily here.
Let's see if I can find a link
https://www.sciencealert.com/paper-suggests-certain-blood-types-might-be-slightly-more-susceptible-to-covid-19
Some Blood Types May Be Slightly More Susceptible to COVID-19, Paper Suggests
Meta-analyses on the pooled data showed that blood group A had a significantly higher risk for COVID-19 compared with non-A blood groups
Whereas blood group O had a significantly lower risk for the infectious disease compared with non-O blood groups."
But the paper also clearly states that although the results were significant, it's not an all-or-nothing result.
As per the study, the normal population in Wuhan has a blood type distribution of 31 percent type A, 24 percent type B, 9 percent type AB, and 34 percent type O.
Those with the virus, by comparison, were distributed as follows: 38 percent type A, 26 percent type B, 10 percent type AB, and 25 percent type O. Similar differences were observed in Shenzhen.