A Neandertal haplotype on chromosome 12 seems protective for severe disease in the current SARS-CoV-2 pandemic. This gene may be present in populations in Eurasia and the Americas at carrier frequencies that often reach and exceed 50%.

The ancestral Neandertal OASlocus variants may thus have been advantageous to modern humans throughout Eurasia, perhaps due to one or many epidemics involving RNA viruses, especially given that the Neandertal haplotype has been found to be protective for at least three RNA viruses (West Nile virus, hepatitis C virus, SARS-CoV).