Coronavirus death rates are almost six times lower in countries that give out the BCG vaccine, experts have discovered.
The century-old jab was developed to protect against the bacterial infection tuberculosis – with children aged ten to 14 getting a mandatory injection.
But as rates of the lung infection dropped, mass vaccination was ditched in the UK in 2005.
Now medics believe the jab could play an important role in the coronavirus pandemic – by turbo-charging the immune system against the bug.
They are looking at whether giving people a new booster jab – or in some cases their first dose – could help protect against coronavirus.
And new research has found that countries that have a widespread BCG vaccination program almost six times lower than nations that don’t use it.
The team, from the US, adjusted for factors which can distort findings – such as a nation’s economic status and its proportion of elderly people.
They then looked at the mortality per one million residents of each country with sufficient data.
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 dis-cernable.”
Their findings were published on MedRxiv – an online archive – and not in a journal as the research is yet to be peer-reviewed by other academics.
For their analysis, the researchers used publicly available data and made an estimate on the case fatality rate from the top 50 countries reporting highest case events.
To make the data more comparable and get around the different epidemic time curves experienced by each country, they calculated days from the 100th Covid-19 positive case.
Those cases and deaths were then compared to BCG vaccination programs in each country.
The average death rate was also found to vary significantly according to a country’s economic classification.
Covid-19 mortality per one million for low-middle-income, upper-middle-income and high-income countries were found to be 0.4, 0.65 and 5.5, respectively.
The team said that the fact the wealthier nations had a higher death rate was “counter-intuitive” but were unable to explain why.
Instead, they pointed to previous research which states “deaths from acute respiratory illness are typically higher in low-income settings due to multiple socio-demographic and economic risk factors”.
The academics said their research should be taken with caution as there are several issues that may skew the findings.
“Despite all these caveats, the inverse relationship between country economic status and Covid-19 attributable mortality, and the strong ecological association with BCG vaccination are intriguing.
“The findings warrant deeper epidemiological scrutiny and prospective evaluation in individually randomized trials.”
Their research comes as scientists across four countries begin trials looking at whether the BCG jab can cut the chances of catching Covid-19.
One team at the Murdoch Children’s Research Institute in Melbourne are fast-tracking large-scale human testing.
Around 4,000 Australian hospital workers are volunteering to take part in the six-month trial, according to Bloomberg.
And a team in the Netherlands are testing the approach on 1,000 healthcare staff.
Leader researcher Nigel Curtis, head of infectious diseases research at the MCRI, said: “It can boost the immune system so that it defends better against a whole range of different infections, a whole range of different viruses and bacteria in a lot more generalized way.
“We wouldn’t be doing this if we didn’t think that this might work.
“We need to think of every possible way that we can protect healthcare workers.” If these trials are successful, it could mean the cheap vaccine could be rolled out to help protect front line staff at high risk.
Peter Openshaw, a professor of experimental medicine at Imperial College London, welcomed the approach.
He says the BCG jab may boost “trained immunity” over the short-term, where the body is on higher alert against infections.
He said: “It means you may be less likely to catch infections during that period because the immune system is more likely to respond very quickly if it spots a foreign invader.”
Other experts were more sceptical about the approach, warning it will at best be a stop gap until a coronavirus vaccine is developed.
Professor Hugh Pennington, from Aberdeen University, said: “We have to try everything, and the BCG may give some benefit – but it should not be seen as the Holy Grail.”
Reporting by Gemma Mullin, Digital Health Reporter.
This article originally posted on The Sun.