Cuba's Soberana 2 vaccine candidate has shown 62 per cent efficacy with just two of its three doses, state-run biopharmaceutical corporation BioCubaFarma has said, citing preliminary data from late-phase trials.

Cuba, whose biotech sector has exported vaccines for decades, has five vaccine candidates in clinical trials, of which two — Soberana 2 and Abdala — are in late-phase trials.

“In a few weeks we should have the results for the efficacy with three doses which we expect will be superior,” said Vicente Vrez, director of the state-run Finlay Vaccine Institute, which developed Soberana 2.