Coronavirus death rates are almost six times lower in countries with a widespread vaccination programme involving the Bacillus Calmette-Guérin (BCG) jab, a new study has found.

The BCG vaccine gives immunity to tuberculosis, but mass vaccination was dropped in the UK in 2005 when rates of the lung infection dropped.

Yet US-based experts now think the vaccine could improve immune systems and protect people from infection.

New research, which is yet to be peer reviewed, suggests that countries with widespread BCG vaccination programmes have much lower rates of the coronavirus than nations without.

Looking at the mortality per one million residents of each country with sufficient data, the researchers made an estimate on the coronavirus fatality rate from the top 50 countries reporting highest case events.

Researchers factored in a nation's economic status as well as its elderly population, factors which could distort the overall picture of death rates.

The Johns Hopkins Bloomberg School of Public Health experts said in their paper: "The intriguing observation of a significant association between BCG use and lower Covid-19-attributable mortality remained discernable.

“While mortality attributable to Covid-19 has devastated global health systems and economies, striking regional differences have been observed.

“Covid-19-attributable mortality among BCG-using countries was 5.8 times lower than in non BCG-using countries.”

The paper was published on the online archive MedRxiv rather than an academic journal as it has not yet been peer-reviewed by other academics.