With the number of deaths related to coronavirus crossing the 50,000-mark globally, a new study has found a link between the universal BCG vaccination and reduced morbidity and mortality for the COVID-19 infection.
A study by the Department of Biomedical Sciences, NYIT College of Osteopathic Medicine, New York Institute of Technology, which is yet to be published highlighted national policies on Bacillus Calmette-Guérin (BCG) vaccination.
BCG vaccination accelerates the secretion of pro-inflammatory cytokines, specifically IL-1B, which has proven to play a vital role in building the antiviral immunity.
Additionally, an earlier study also found that children vaccinated with BCG were observed to have a 50% reduction in overall mortality, which was attributed to the vaccine’s effect on reducing respiratory infections and sepsis.
BCG is a live attenuated strain derived from an isolate of Mycobacterium bovis used widely across the world as a vaccine for Tuberculosis (TB), with many nations, including Japan and China, having a universal BCG vaccination policy in newborns.
It was found that middle-high and high-income countries which have a current universal BCG policy (55 countries) had 0.78 deaths per million people.
On the contrary, the middle-high and high-income countries that never had a universal BCG policy (5 countries) had a larger mortality rate of 16.39 per million people.
The study, specifically, noted the differences in the numbers among different countries.
“Iran has a current universal BCG vaccination policy but it just started in 1984, and has an elevated mortality with 19.7 deaths per million inhabitants. In contrast, Japan started its universal BCG policy in 1947 and has around 100 times less deaths per million people, with 0.28 deaths. Brazil started universal vaccination in 1920 and also has an even lower mortality rate of 0.0573 deaths per million inhabitants,” stated the New York study.
It also pointed out that with the number of tuberculosis cases reducing in the late 20th century, several middle-high and high-income countries in Europe dropped the universal BCG policy between 1963 and 2010.
One of the worst-hit countries — Italy, where the mortality due to COVID-19 is very high — never implemented universal BCG vaccination, said the study.
An epidemiological observation
Dr N Kumarasamy, chief and director, Voluntary Health Services – Infectious Diseases Medical Centre and director, Chennai Antiviral Research and Treatment (CART) Clinical Research Site of US National Institutes of Health (NIH), said that such studies can be validated only after more reports of tests being conducted.
“This is an epidemiological observation and we need more time to understand how the disease has spread in continents like Africa. At the moment, only South Africa is testing and BCG vaccine is also part of the immunization programme in African countries, apart from Eastern European countries like Russia, Poland and Czech Republic and countries in Asia like India,” he added.
Dr Kumarasamy also pointed out that the BCG vaccine is for bacterial diseases such as TB while COVID-19 is a viral disease.
“Once the data is available about the deaths from all countries with BCG as part of their immunisation programme, we need to look into the science and focus on the vaccine – if it has a protein that can be a protective cover against the virus. As of now, we know that BCG is a good vaccine and is effective as a cover against only some types of TB like in lymphnodes and brain,” he said.