BLACKSBURG, Va. — Health officials and doctors have been proclaiming for months now that developing countries may end up being the hardest hit by the coronavirus. Surprisingly, however, up to this point, many developing nations are actually reporting lower COVID-19 mortality rates than expected. Despite a limited healthcare infrastructure, how are developing nations faring so well against the coronavirus? A new study from Virginia Tech is offering up an explanation.
Researchers theorize that Bacille Calmette-Guérin (BCG), a tuberculosis vaccine regularly given to children in nations with high rates of the disease, may be weakening the virus within many patients.
“In our initial research, we found that countries with high rates of BCG vaccinations had lower rates of mortality,” explains Assistant Professor Luis Escobar of the College of Natural Resources and Environment in a university release. “But all countries are different: Guatemala has a younger population than, say, Italy, so we had to make adjustments to the data to accommodate those differences.”
Germany the perfect sample
In collaboration with the National Institutes of Health, Escobar gathered coronavirus mortality data from all over the planet. Even after adjusting for various factors (income, access to healthcare, population size, etc), a correlation was observed: countries with higher rates of BCG vaccinations showed lower peak COVID-19 mortality rates.
One nation of particular interest for these purposes was Germany. Prior to East and West German reunification in 1990, the two halves of the European nation had different vaccination policies. West Germany administered BCG vaccines to infants between 1961 and 1998, while East Germany did the same between 1951 and 1975. So, if the vaccine really does weaken the coronavirus, that would mean older Germans (the most at risk demographic) born in the country’s eastern portion would have more protection against COVID-19 than their peers born in the west.
Sure enough, the German data supports this theory: Western German states have a mortality rate that is 2.9 times higher than that of East Germany.
“The purpose of using the BCG vaccine to protect from severe COVID-19 would be to stimulate a broad, innate, rapid-response immunity,” Escobar says.
Also, this isn’t the first time the BCG vaccine has shown the ability to help with issues besides tuberculosis. In the past it has seemingly helped protect against other viral respiratory illnesses.
More research on tuberculosis vaccine as COVID-19 shield
These findings are still very preliminary, and the study’s authors caution that much work is ahead before any final conclusion can be drawn. Moreover, as of now, the WHO’s stance on the BCG vaccine is that there is no conclusive evidence it can help people dealing with COVID-19. As such, they recommend that no one get the vaccine solely to prevent or fight a COVID-19 infection. There are, however, already numerous clinical trials underway focusing on BCG and its possible coronavirus benefits.
“We’re not looking to advise policy with this paper,” Escobar notes. “This is, instead, a call for more research. We need to see if we can replicate this in experiments and, potentially, in clinical trials. We also need to come back to the data as we get more information, so we can reevaluate our understanding of the coronavirus pandemic.”
The study is published in Proceedings of National Academy of Sciences.