The World Health Organisation (WHO) estimates that BCG coverage in South Africa has been at between 80% and 90% in most years since 1973.
The organisation further advises caution, however, as clinical trials will be needed to establish any positive Covid-19 link. But a proper vaccine could take another 18 months to develop and it will take far less time to determine whether the already available BCG vaccine offers some protection against the more severe effects of Covid-19.
The NYIT study’s authors have said: “Covid-19 has spread to most countries in the world. Puzzlingly, the impact of the disease is different in different countries. These differences are attributed to differences in cultural norms, mitigation efforts, and health infrastructure.
“Here we propose that national differences in Covid-19 impact could be partially explained by the different national policies with respect to BCG childhood vaccination.
“BCG vaccination has been reported to offer broad protection to respiratory infections. We compared large numbers of countries’ BCG vaccination policies with the morbidity and mortality for Covid-19. We found that countries without universal policies of BCG vaccination (Italy, Netherlands, USA) have been more severely affected compared to countries with universal and long-standing BCG policies.
“Countries that have a late start of universal BCG policy (Iran, 1984) had high mortality, consistent with the idea that BCG protects the vaccinated elderly population. We also found that BCG vaccination also reduced the number of reported Covid-19 cases in a country. The combination of reduced morbidity and mortality makes BCG vaccination a potential new tool in the fight against Covid-19.”