Can a 100-Yr-Old TB Vaccine Work Against COVID-19? Experts Differ
Studies claim a correlation between universal BCG vaccination policy and reduced mortality for COVID-19.
Who would have thought that a 100-year-old vaccine would be brought into a discussion about a possible treatment for a never-seen-before virus.
The whole world is looking at researchers, virologists and vaccine experts with hope as they continue to study and test out vaccinations that have been known to boost immunity, reduce respiratory symptoms and create antibodies in the body to fight against pathogens.
Among various vaccinations that are being tested against the coronavirus, is BCG, a vaccination used to immunize against TB. Countries that have historically suffered from the disease for years have the provision of administrating BCG at birth, India is one such example. India has been inoculating its population with BCG since 1948.
Over the years, Bacille Calmette-Guerin (BCG) has been known to do more than preventing the spread of TB. Experts believe that this vaccine reduces the scope of respiratory infection and helps in dealing with meningitis and leprosy. It also prepares the immune system to respond better to infections.
Considering the various immunological benefits of BCG, experts across the world are trying to find a link between BCG and COVID-19. Every day researchers and doctors are making progress in solidifying this correlation that some are sure, exists.
On the one hand, countries like Australia and Germany are testing BCG on healthcare workers to confirm its efficacy and on other, studies are being published claiming countries that already have universal BCG vaccination policies in place have less mortality rate due to coronavirus.
In this article, we will answer your questions related to BCG and put forward what the experts have to say:
'Correlation Between Universal BCG Vaccination Policy & Reduced Mortality for COVID-19': Studies
A study posted on MedRxix says countries without universal policies of BCG vaccination such as Italy, Nederland and USA have been more severely affected by COVID-19 compared to countries with universal and long-standing BCG policies.
It further adds,
"The correlation between the beginning of universal BCG vaccination and the protection against COVID-19 suggests that BCG might confer long-lasting protection against the current strain of coronavirus."
Gonzalo Otazu, Assistant Professor of biomedical sciences at NYIT and lead author of this study said, he knew about BCG vaccine providing protection against other contagions so he and his team looked at the data on countries who had such policy in place and number of confirmed COVID-19 cases to find a correlation, Bloomberg reported.
Another study co-authored by an Indian-American cancer surgeon and professor of cancer research at MD Anderson Cancer Center in Houston, Dr. Ashish Kamat says, "The incidence of COVID-19 was 38.4 per million in countries with BCG vaccination compared to 358.4 per million in the absence of such a program." This study analysed data from 178 countries.
His study further adds,
"The death rate was 4.28/million in countries with BCG programs compared to 40/million in countries without such a program."
'Correlation is Not Causation': Other Expert Reports Challenge the Claim
Another report published as "critique of an ecological study", written by Emily MacLean from McGill university argues, "correlation does not imply causation.”
"It may emerge that the BCG vaccine does confer protection against COVID-19; however, with the current state of knowledge we cannot state this with any degree of certainty", she adds. Maclean also says that there is a danger in taking such findings at face value as it has the potential for complacency in response to the pandemic.
"There is danger in citing that there is evidence that a century-old vaccine may boost immunity in individuals, providing non-specific protection to other illnesses, and by extension protecting against COVID-19 or reducing the severity of its presentation based on this analysis alone", she further emphasises.
'Too Early to Say': Experts & Doctors From India Say
FIT spoke to experts to understand if the said correlation holds a strong ground.
Dr. Jacob T John, veteran virologist told us that the fundamental basis of the likelihood of BCG helping in COVID-19 is the possibility that BCG somehow modifies the immune system against respiratory infection.
He, however, added that the old version of BCG can't be trusted, the modified version can still be looked at. He also highlighted that the protection provided by BCG is not uniform across all age groups and the world.
He, further, said:
"It is only after getting results from the concrete studies done by Australia and Germany, we can be sure. Until then, it is just a theory. India on the other hand can't afford to be distracted by the research work right now. We are fighting a war. We should concentrate on protecting the health workers."Dr. Jacob John, Virologist
Suranjit Chatterjee, Senior Internal Medicine Specialist at Apollo Hospital, while talking to FIT said the studies that are being done right now are observational but we have to wait for confirmation.
On the question of how hopeful India can be about these new studies, he said, "India might be more immune to COVID-19 than any other country because of the infections present here. BCG works the same way. But to say that BCG will certainly work for us is wishful thinking".
Trials in Various Countries to Check Efficacy of BCG
Various trials and tests are underway in some Europian countries and Australia to check if BCG can indeed work against COVID-19.
Researchers from the Murdoch Children’s Research Institute (MCRI) in Australia are doing this trail on 4000 healthcare workers.
“This trial will allow the vaccine’s effectiveness against COVID-19 symptoms to be properly tested, and may help save the lives of our heroic frontline healthcare workers,” MCRI Director Professor Kathryn North said in a release, Forbes reported.
Similar tests are being done in Germany, Netherlands, and Greece.
Earlier, experts at the Max Planck Institute for Infection Biology developed a vaccine based on BCG. It will soon be tested against coronavirus. The said vaccine, VPM1002 is believed to protect people from respiratory problems.
The institute says,
"The large-scale study is to be carried out at several hospitals in Germany and will include older people and health care workers. Both groups are particularly at risk from the disease. VPM1002 could thus help bridge the time until a vaccine specifically effective against SARS CoV-2 is available."
Caution & Patience Needed
While all eyes are on these testings and reports, it is important to note that as of now, we don't have solid proof that the BCG will indeed work and if countries with universal BCG policy can be sure of their immunity. It is paramount that all the safety measures - self-isolation being the biggest one - should be followed without a fail.
More updates on this follow in the weeks to come but it should be kept in mind that BCG may not be for people with compromised immune systems or pregnant women. Even those who believe in the efficacy of BCG against coronavirus agree that it is not a permanent solution and until the dedicated vaccine for COVID-19 is introduced, a 100-year-old TB vaccine can be tested and then put in use for immunity boosting.
“No country in the world has managed to control the disease just because the population was protected by BCG”, says Otazu who co-authored the study that claims countries will universal vaccine policy has less mortality rate against COVID-19.
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