There is this paper on it. It suggests there may be a relatively small advantage to certain blood types. The best blood type according to this particular study is O+. In the other groups, (-) was better than (+).

Frankly though, the statistical significance was small, and given that sars-cov-2 testing itself is compromised, I don't have any faith in any such study. Even if all that is true however, I don't fall into any of the beneficial categories, so its not applicable to me. :-)