The US biotech firm Inovio reported preliminary but encouraging results Tuesday from tests of an experimental coronavirus vaccine. AFP reports that the vaccine, administered to 40 volunteers, triggered an immune system response in 94 percent of those who completed the so-called phase one clinical trial, meaning they received two injections, four weeks apart. Inovio’s vaccine, called INO-4800, is designed to inject DNA into a person so as to set off a specific immune system response against the SARS-CoV-2 virus.