The variants may affect the activity or function of genes involved in a biochemical chain reaction that ends with the destruction of viral RNA, including the coronavirus’s. The protective variants are largely absent among people in sub-Saharan Africa, where few people carry genes inherited from Neandertals. About 25 to 30 percent of present-day people of Asian and European ancestry carry the protective variants. Some Black people in the Americas also inherited the protective haplotype, presumably from Asian, European or Native American ancestors.
You can read more at https://www.pnas.org/content/118/9/e2026309118.