They are looking at whether the Neanderthal chromosome #3 or the Alzheimer Gene make a difference as to how your body reacts to the virus.
Neanderthal issue is more common in Europeans
There are probably multiple genetic quirks that make you susceptible. Whether they find them or not is another story.
O blood and Alzheimers
O blood and Covid
O blood and Malaria
Maybe Covid will help them find a clue as to Alzheimers
https://www.nytimes.com/2020/07/04/health/coronavirus-neanderthals.html
This piece of the genome, which spans six genes on Chromosome 3, has had a puzzling journey through human history, the study found. The variant is now common in Bangladesh, where 63 percent of people carry at least one copy. Across all of South Asia, almost one-third of people have inherited the segment.
Elsewhere, however, the segment is far less common. Only 8 percent of Europeans carry it, and just 4 percent have it in East Asia. It is almost completely absent in Africa.