Early data from trials of three potential COVID-19 vaccines released on Monday, including a closely-watched candidate from Oxford University, increased confidence that a vaccine can train the immune system to recognize and fight the novel coronavirus without serious side effects. The vaccine being developed by British drugmaker AstraZeneca along with the Oxford University, induced an immune response in all study participants who received two doses without any worrisome side effects. A coronavirus vaccine under development by CanSinoBiologics Inc and China’s military research unit, likewise showed that it appears to be safe and induced an immune response in most of the 508 healthy volunteers who got one dose of the vaccine, researchers reported. Some 77% of study volunteers experienced side effects like fever or injection site pain, but none considered to be serious. German biotech BioNTech and U.S. drugmaker Pfizer Inc released details from a small study in Germany of a different type of vaccine that uses ribonucleic acid (RNA) - a chemical messenger that contains instructions for making proteins. In the not-yet peer reviewed study of 60 healthy adults, the vaccine induced virus-neutralizing antibodies in those given two doses, a result in-line with a previous early-stage U.S. trial.