https://www.scientificamerican.com/article/coronavirus-vaccine-is-90-percent-effective-in-large-trial-pfizer-says/

Pfizer and BioNTech announced today that their experimental vaccine against the novel coronavirus is more than 90 percent effective in preventing the disease COVID-19, based on initial analysis of results from their large phase III trial. The two companies also report that no serious safety concerns have arisen thus far. To create the vaccine, researchers genetically engineered SARS-CoV-2 genes, captured their blueprint, embedded that blueprint into an RNA molecule in solution and injected the solution into the bodies of trial participants. The full method for this approach is outlined in the graphic below (light blue boxes), which originally appeared in the June 2020 issue of Scientific American. The trial’s data have not yet been submitted for peer-review publication. If the results hold up, Pfizer and BioNTech say they could manufacturer large quantities of the genetically engineered vaccine quickly.