The US Food and Drug Administration has issued an emergency use authorisation to Moderna Inc for a vaccine for Covid-19 following trial data showing it was 94.1% effective in preventing the disease. The decision comes just a week after the agency issued an emergency authorisation for a vaccine developed by BioNTech SE and its partner Pfizer Inc. Both vaccines are based on messenger RNA (mRNA), a technology never before used in a human vaccine. The two vaccines work by instructing cells in the body to make copies of the SARS-CoV-2 spike protein.
