China’s jabs may have an important role

IN MEDICAL SCIENCESARSCV, fortune rarely favours endeavours that begin by skirting phase-three trials—those that test a new drug or vaccine on lots of people in a rigorously controlled way. Yet this is exactly how a number of Chinese covid-19 vaccines arrived in the world last year.Rumours started in June that workers at Beijing airport were being given untested vaccines. As the year progressed, health officials confirmed that China had started mass inoculations—even though vaccines against -o-2, the virus that causes covid-19, had not been through phase-three trials in the country. By November, one of these vaccines had been given to nearly 1m people. Scientists abroad fretted over the safety of such a huge, uncontrolled experiment.