An experimental coronavirus vaccine developed by Inovio Pharmaceuticals Inc showed promise. It was found to be safe in an early-stage human trial, the company said on Tuesday. The vaccine is one of 17 being tested in humans and part of the Trump administration's Operation Warp Speed program. It induced immune responses in 34 of the 36 healthy volunteers aged 18 to 50 years. More studies would be needed to show if the antibody and other responses mean the drug can stop the virus in humans. | The