Most Americans are eagerly awaiting FDA approval of COVID vaccines. So are healthcare workers, especially those on the front lines of the pandemic. We know that there are skeptics. There are people who are concerned that the vaccines have been developed very quickly. We will not shame the skeptics. And we understand that some people may want to wait and see how the initial volunteers fare with the coronavirus vaccine. There is another vaccine that might work, though. It is the Bacillus Calmette-Guerin or BCG vaccine. It has been around a long time.
The BCG Vaccine Has Existed for Over 100 Years!
A new study published in the Journal of Clinical Investigation (Nov. 19, 2020) has revealed that a very old vaccine may also protect against COVID-19. The BCG vaccine has been available for more than a century to prevent tuberculosis. The FDA has also approved BCG as an immunotherapy to treat bladder cancer.
The authors of this study point out that:
“Bacillus Calmette-Guérin (BCG) is a live-attenuated vaccine strain of Mycobacterium bovis used against tuberculosis, however various studies have demonstrated that the BCG vaccine also induces potent and non-specific protection against other non-related diseases. Early administration of the BCG vaccine reduces child mortality by ~38-45%, mainly as a result of decreased neonatal sepsis, respiratory infections, and fever. Non-specific effects of BCG vaccination are not limited to children, as BCG vaccination in adolescents leads to a 70% decrease in the incidence of respiratory tract infections, and BCG-vaccinated elderly people (age 60-75) also experience fewer respiratory infections.”
The BCG vaccine stimulates what is called the body’s innate immune system. This trained immunity leads to activated natural killer (NK) cells and macrophages. These are the body’s first line of defense against invading viruses and other organisms. You can learn more about this aspect of the immune system by listening to our podcast with a noted virologist and immunologist at this link.
Show 1233: How Does Your Immune System Overcome Viruses?
Understanding innate immunity can help us appreciate how can the immune system overcome viruses, including SARS-CoV-2.
The Results of the BCG Vaccine Study:
In the new study, over 6,000 healthcare workers were tested for SARS-CoV-2 antibodies. They also provided information about prior vaccinations. People who had received a BCG vaccination were much less likely to have developed COVID-19.
Here is what the authors concluded:
“Overall, in our cohort of HCWs [health care workers], we observe a protective and non-specific association between history of BCG vaccination and reduced SARS-CoV-2 infection, seroprevalence, as well as presence of COVID-19-related symptoms. The reported observation that BCG vaccination might be effective against SARS-CoV-2 infection and could potentially be used preventively to prevent COVID-19 needs to be further confirmed by randomized placebo-controlled blinded clinical trials, which are currently underway.”
Other Studies of BCG Against COVID-19:
Lest you think this is pie in the sky, there are randomized controlled trials underway at a number of major health centers including the University of Texas MD Anderson Cancer Center and Baylor College of Medicine. There are medical centers in the Netherlands that are recruiting volunteers for a BCG vaccine trial against COVID-19. Researchers in South Africa are also recruiting subjects for a similar trial.
BCG Vaccine vs TB:
It is estimated that over 100 million kids get a BCG vaccine every year to prevent tuberculosis. Although TB is not common in many developed countries, it is a killer around the world.
An article published in EMBO Molecular Medicine back on May 8, 2020, describes the Japanese situation:
“Japan, like many other countries including China, Korea, India, and the Russian Federation, have mandatory childhood BCG vaccines against tuberculosis. These countries have so far a relatively low per capita death rate from COVID‐19 compared to countries that have no mandatory BCG vaccines (USA, Spain, France, Italy, The Netherlands)…This association between BCG vaccination and apparent low COVID‐19 incidence in Japan has spurred the idea that these two things may be linked.”
BCG Vaccine vs. COVID-19: A Canadian Perspective
An article published in the Canadian Journal of Public Health (Nov. 19, 2020) offers this overview of the BCG vaccine:
“Currently, there is a widespread discussion in the scientific community regarding BCG vaccination as an effective intervention to mitigate the COVID-19 pandemic. The objective of this short commentary is to briefly present the state of knowledge and perspectives regarding the potential of BCG studies and vaccination in the Canadian context.
“Since the beginning of the COVID-19 pandemic, randomized clinical trials have been launched to assess BCG protection, targeting health care workers mainly. A total of 19 phase 3 trials in 13 countries were registered in ClinicalTrials.gov as of September 30, 2020, and first results are expected in early 2021. One of these trials is conducted by the University Health Network in Toronto.”
The BCG vaccine has a 100-year history. The FDA has approved this vaccine for treating bladder cancer. People who are traveling to countries with a high incidence of tuberculosis can also get a BCG shot. If randomized clinical trials demonstrate that this vaccine can help protect against COVID-19, we suspect that manufacturing would gear up quickly. The cost should be quite affordable. Stay tuned for the latest research in our newsletter.