A Spanish study has cast doubt on the feasibility of herd immunity as a way of tackling the coronavirus pandemic, the BBC reports.
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 infected with 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.
“Despite the high impact of Covid-19 in Spain, prevalence estimates remain low and are clearly insufficient to provide herd immunity,” the study’s authors said in the report.
“This cannot be achieved without accepting the collateral damage of many deaths in the susceptible population and overburdening of health systems.
“In this situation, social distance measures and efforts to identify and isolate new cases and their contacts are imperative for future epidemic control.”
The study is thought to be the largest of its kind on the coronavirus in Europe.