Bacillus Calmette-Guérin (BCG) vaccine is has been given to newborns primarily against tuberculosis (TB) and leprosy in developing countries – in Africa, Asia, the Middle East, Central and South America and parts of Central Europe. First used medically in 1921, it is now given to almost 100 million babies around the world each year.
Only Indigenous Canadian communities currently receive the vaccine, but the US has never used mass immunization of BCG, relying instead on the detection and treatment of latent TB. The shot was given to all Israeli newborns between 1955 and 1982, after which it was no longer needed.
But now, Israeli researchers have found a new use for BCG vaccine.
Vaccinations given against TB the last 15 years may provide additional protection against COVID-19 to people under 24 years of age, according to a new study published recently in the journal Vaccines under the title “Significantly Improved COVID-19 Outcomes in Countries with Higher BCG Vaccination Coverage: A Multivariable Analysis.”
Dr. Nadav Rappoport of the software and information systems engineering department of Ben-Gurion University of the Negev in Beersheba worked with colleagues from the Hebrew University of Jerusalem to analyze the correlation between countries’ policies for the BCG vaccine for tuberculosis and countries’ COVID-19 outcomes.
They discovered that giving BCG injections, which are safe with rare and mild side effects, are associated with some protection from COVID-19 – either reducing infection rates or reducing death rates. The protection was significant among those 24 years old and younger who had received the vaccination in the last 15 years. There was no effect among older adults who had received the BCG vaccine years ago.
Rappoport and his colleagues analyzed normalized data from 55 countries around the world, which comprise 62.9% of the world’s population. To normalize the data, they included countries with populations more than three million. As the pandemic reached different countries at different dates, they aligned countries by the first date at which the country reached a death rate of 0.5 deaths per million or higher. They controlled for demographic, economic, pandemic-restriction-related and health-related country-based variables.
Their data revealed the BCG vaccine was consistently in the top two beneficial effects across the 55 countries. To determine whether other vaccines also influenced COVID-19 outcomes, they conducted the same analysis for the measles and rubella vaccines. They found that those vaccines have no significant association with COVID-19 outcomes.
Other epidemiological studies have shown the effect of the BCG vaccine beyond tuberculosis, but scientists do not yet know why the vaccine has such an effect. “Our findings suggest exploring BCG vaccine protocols in the context of the current pandemic could be worthwhile,” concluded.