Nations that mandate TB vaccine may have lower Covid death rates

To be sure, scientists have not been able to determine a clear correlation between the severity of the coronavirus disease and neonatal BCG vaccination.

Countries that mandate the Bacillus Calmette-Guérin (BCG) vaccine for newborns to prevent tuberculosis, including India, Peru, Portugal and Saudi Arabia, have fared 3.4 times better on the Covid-19 fatality rate (CFR) than nations that haven’t made the vaccine obligatory, like Belgium, the Netherlands, Switzerland and Ecuador, though the last two still appear to be benefitting from their past use of the vaccine.

The World Health Organization (WHO) says that two clinical trials addressing the question of BCG offering protection against Covid-19 are underway(AP)

That’s the finding of a HT analysis of the current fatality rate (CFR) in the eight nations that had between 20,000 and 50,000 Covid-19 cases each on Wednesday morning.

The analysis appears to support an yet-to-be peer-reviewed study conducted by a group of US researchers which found that countries without universal policies of BCG vaccination (Italy, the Netherlands and the United States) have been more severely affected compared to countries with universal and longstanding BCG policies such as India and China. The study was published in the preprint health sciences server, medRxiv, on March 28 .

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To be sure, scientists have not been able to determine a clear correlation between the severity of the coronavirus disease and neonatal BCG vaccination. The World Health Organization (WHO) says that two clinical trials addressing the question of BCG offering protection against Covid-19 are underway.

On average, 2.65% of people who have been infected with the Sars-Cov-2 virus in the four nations that have mandatory BCG vaccination programmes have died, according to the study. In the four that do not prescribe mandatory neonatal BCG vaccination, an average of 9.19% of confirmed Covid-19 patients have died.

This means that on average, a person is 3.4 times more likely to die if he or she gets infected by Sars-Cov-2 in Belgium, the Netherlands, Switzerland and Ecuador than in India, Peru, Portugal and Saudi Arabia, .

Portugal,which reported 948 deaths from 24,322 cases, has the highest CFR (3.9%). India, with 1,007 deaths from 31,329 cases, has a CFR of 3.2%. Peru (31,190 cases and 854 deaths) has a CFR of 2.7% and Saudi Arabia has a CFR of 0.8% (20,077 cases and 157 deaths). (Chart 1)

Ecuador and Switzerland had mass BCG vaccinations programmes until as late as the 1980s. This may be the reason why these two countries fare better than Belgium and Netherlands which have not had mass BCG immunisation in the recent past.

Of the four counties that do not insist on mandatory BCG vaccination of newborns, Belgium has 47,334 cases and 7,331 deaths (CFR: 15.5%). The Netherlands has reported 38,416 cases with 4,566 deaths (CFR of 11.9%). Switzerland has a CFR of 5.8% with 29,264 cases and 1,699 deaths and Ecuador has a CFR of 3.6% with 24,258 cases and 871 deaths.

The study by US researchers also found that the onset of the coronavirus disease had been abrupt in the non-BCG nations while cases of the disease emerged more gradually in countries with the mandatory vaccination programmes. (Chart 2)

Experts, however, said that besides than BCG vaccinations other factors like age, comorbidity, social distancing and lockdowns may be influencing the outcome of Covid-19 cases.

“Developing countries may have BCG vaccinations but they also have a younger population. If say 30% of the population is above the age of 60%, then you may expect higher mortality. So, you may think that it is BCG vaccination that is causing the lower death rate, but it just may be the age or the fact that younger people have fewer comorbid conditions. We can’t know for sure just yet,” said T Jacob John, former head of the Indian Council for Medical Research’s Centre for Advanced Research in Virology.