The study of more than 60,000 people estimates that around just 5% of the Spanish population has developed antibodies, the medical journal the Lancet reported.

Herd immunity is achieved when enough people become immune to a virus to stop its spread.

Around 70% to 90% of a population needs to be immune to protect the uninfected.

The prevalence of Covid-19 antibodies was below 3% in coastal regions, but higher in areas of Spain with widespread outbreaks, the report said.

Read MORE

BBC NEWS