Last year, researchers at Karolinska Institutet in Sweden and the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany showed that a major genetic risk factor for severe COVID-19 is inherited from Neandertals. Now the same researchers show, in a study published in PNAS, that Neandertals also contributed a protective variant. Half of all people outside Africa carry a Neandertal gene variant that reduces the risk of needing intensive care for COVID-19 by 20 percent.