A vaccine developed in China appears to be safe and may protect people from the new coronavirus, researchers reported on Friday. Apoorva Mandavilli writes in the New York Times that the early-stage trial, published in The Lancet, was conducted by researchers at several laboratories and included 108 participants aged 18 to 60. Those who received a single dose of the vaccine produced certain immune cells, called T cells, within two weeks. Antibodies needed for immunity peaked at 28 days after the inoculation.