A UK coronavirus vaccine trial now only has a 50% chance of success, a leading scientist has warned. Professor Adrian Hill, whose team at Oxford University are racing to develop a jab, had originally hoped their efforts would be proved successful by September.
But the researchers have suffered a setback because as coronavirus infections plummet in the UK, they cannot be sure their inoculation works, the Telegraph reports.
The Oxford vaccine is one of eight around the world and just one in the UK which is currently being tested in humans. Earlier in the year, scientists said they were "80% confident" it would be proved effective by the autumn, making it one of the most promising candidates in the world.