'Sun, sea, sand and Soberana 02': Cuba open to inoculating tourists with homegrown Covid vaccine CNBC 2/23/2021 Sam Meredith Soberana 02 is due to enter Phase 3 trials from March 1, and officials say tests will include as many as 150,000 volunteers within weeks. If it is found to be safe and effective, the development of a domestically produced Covid vaccine would likely be hailed as an astonishing scientific breakthrough and a significant political triumph. It comes at a time when many people in Cuba are forced to wait in line for hours to buy basic goods and as authorities continue to navigate a decades-old U.S. trade embargo.