The Food and Drug Administration (FDA) issued new rules on Tuesday for the companies developing COVID-19 vaccines. "While the FDA is committed to help expedite this work, we will not cut corners in our decision making, and we're making clear in our guidance what are the data that we need, that should be submitted, to meet our regulatory standards of approval," FDA commissioner Dr. Stephen Hahn said Tuesday during a Senate committee hearing. The guidance states that the primary efficacy endpoint in a placebo-controlled efficacy clinical trial should be at least 50%, meaning the vaccine needs "to reduce the risk of disease caused by COVID-19 by 50%" when compared to the placebo, according to Brad Loncar, a longtime biotech investor and CEO of Loncar Investments. There are a number of drugmakers developing COVID-19 vaccine candidates including AstraZeneca /zigman2/quotes/200304487/composite AZN -1.08% and the University of Oxford, Inovio Pharmaceuticals Inc. /zigman2/quotes/202993817/composite INO -3.39% , and Moderna Inc. /zigman2/quotes/205619834/composite MRNA +4.33% , two of which (Inovio and Moderna) have disclosed preliminary data from their Phase 1 trials. A return to economic normalcy has largely been tied to the arrival of vaccines that can prevent infections from the coronavirus. "There is no guarantee...that we will have a safe and effective vaccine, but we are cautiously optimistic," Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, testified during the same hearing.