This picture taken on May 23, 2020 shows a tray with doses of a COVID-19 novel coronavirus vaccine candidate ready for trial on monkeys at the National Primate Research Center of Thailand at Chulalongkorn University in Saraburi. - After conclusive results on mice, Thai scientists from the centre have begun testing a COVID-19 novel coronavirus vaccine candidate on monkeys, the phase before human trials. (Photo by Mladen ANTONOV / AFP) (Photo by MLADEN ANTONOV/AFP via Getty Images)