A health worker sorts blood samples for Covid-19 vaccination study at the Center for Pediatrics Infectology Studies (CEIP) where the pharmaceutical company Janssen, of Johnson & Johnson, is developing the phase 3 study of the vaccine in Cali, Colombia on November 26, 2020. – The World Health Organization (WHO) has identified 48 “candidate vaccines” at the stage of clinical trials in humans by mid-November, but only 11 at the most advanced Phase 3 stage. The WHO has identified another 164 vaccine projects that are still in the pre-clinical phase of development. (Photo by Luis ROBAYO / AFP)
