I know of no natural virus that discriminates based on race and I suspect it's really hard to find a smallish set of genes that let you discern, say, Europeans

I know of no natural virus that discriminates based on race and I suspect it's really hard to find a smallish set of genes that let you discern, say, Europeans from Russians with high accuracy. I'd like to see some papers about gene-targeted viruses, because I don't believe that they're realistic.