Scientists in the UK have begun testing the BCG vaccine, developed in 1921, to see if it can save lives from Covid, - BBC reports.
The vaccine was designed to stop tuberculosis, but there is some evidence it can protect against other infections as well.
Around 1,000 people will take part in the trial at the University of Exeter.
But while millions of people in the UK will have had the BCG jab as a child, it is thought they would need to be vaccinated again to benefit.