Five key genes are linked with the most severe form of Covid-19, scientists said, in research that also pointed to several existing drugs that could be repurposed to treat people who risk getting critically ill with the pandemic disease.

Once touted as promising treatments and by some even a cure, the World Health Organization dashes those claims, finding no benefit in the use of four popular Covid-19 treatments (remdesivir, hydroxychloroquine, lopinavir, or interferon-beta-1a) on hospitalized patients.