Merck & Co Inc and its partner Ridgeback Biotherapeutics LP published new efficacy data for their Covid-19 treatment on 26 November showing that the anti-viral drug reduced the risk of hospitalisation or death by 30%, compared with a placebo, instead of the earlier reported 50%. The updated efficacy figure is based on additional data presented to the US Food and Drug Administration. The FDA’s Antimicrobial Drugs Advisory Committee was scheduled to meet on 30 November to evaluate the latest information.