Srinagar, Mar 31: Remember the BCG shots we all have received in our childhood! Well, according to a March 28 study, the countries with universal policies of BCG vaccination including India could have better chances against coronavirus than those that did not have such a policy in place.
The findings published by NYIT College of Osteopathic Medicine (NYITCOM), researchers, led by Gonzalo Otazu, Ph.D., assistant professor of biomedical sciences reveal the Bacillus Calmette-Guerin (BCG) vaccine, also known as tuberculosis (TB) vaccine, could be a potential weapon in combatting the deadly coronavirus.
“We found that countries without universal policies of BCG vaccination, such as Italy, the Netherlands, and the United States have been more severely affected compared to countries with universal and long-standing BCG policies,” the researchers said in an official statement on Monday.
According to the study accessed by The Kashmir Monitor, the vaccination is believed to offer broad-ranging protection against respiratory infections, which present similar symptoms to COVID-19.
“The broad use of the BCG vaccine across a population could reduce the number of carriers, and combined with other measures could act to slow down or stop the spread of COVID-19,” the study says.
As one of the most widely used vaccines in the world, the BCG vaccine has existed for nearly a century and has been shown to be an effective tool in preventing meningitis and disseminated TB in children.
“Several vaccines including the BCG vaccination have been shown to produce positive ‘heterologous’ or non-specific immune effects leading to improved response against other nonmycobacterial pathogens…This phenomenon was named ‘trained immunity’ and is proposed to be caused by metabolic and epigenetic changes leading to promotion of genetic regions encoding for pro-inflammatory cytokines…,” it reads.
Dr Otazu, who is also a researcher in the new Center for Biomedical Innovation, completed the study with the assistance of NYITCOM students Aaron Miller, Mac Josh Reandelar, Kimberly Fasciglione, and Violeta Roumenova, along with Center technician Yan Li.
The team compared various nations’ BCG vaccination policies with their COVID-19 morbidity and mortality and found a significant positive correlation between the year when universal BCG vaccination policies were adopted and the country’s mortality rate.
In other words, the earlier a policy was established, the more likely that a significant portion of the population, especially the elderly, would be protected.
“For example Iran, which has a current universal BCG vaccination policy that only started in 1984, has an elevated mortality rate with 19.7 deaths per million inhabitants. In contrast, Japan, which started its universal BCG policy in 1947, has approximately 100 times fewer deaths per million people, with 0.28 deaths. Furthermore, Brazil started universal vaccination in 1920 and has an even lower mortality rate of 0.0573 deaths per million inhabitants,” the study reads.
India started BCG vaccination of children in 1949, and currently 97% of 26 million children born in India receive the BCG vaccine free. India’s universal immunisation programme, under which the BCG vaccine is given, went up to the current figure of 97%, according to the ministry of health and family welfare data.
The vaccine is manufactured in India, and costs less than Rs 100 per vial in the private sector.
“We found that countries without universal policies of BCG vaccination (Italy, Nederland, USA) have been more severely affected compared to countries with universal and long-standing BCG policies,” the study says.
It also answers why Covid-19 spread in China despite children getting BCG vaccinated since the 1950s.
“During the Cultural Revolution (1966-1976), tuberculosis prevention and treatment agencies were disbanded and weakened. We speculate that this could have created a pool of potential hosts that would be affected by and spread Covid-19,” said the study.
So why do some nations vaccinate while others do not?
As TB cases fell in the late 20th century, several higher-income countries in Europe dropped their universal BCG policies between 1963 and 2010. In the United States, the CDC currently recommends the BCG vaccine only for very select persons who meet specific criteria and in consultation with a TB expert.
Among the 180 countries with BCG data available today, 157 countries currently recommend universal BCG vaccination. The remaining 23 countries have either stopped BCG vaccination due to a reduction in TB incidence or have traditionally favoured selective vaccination of “at-risk” groups.
Methods and results
The team collected the BCG vaccination policies across countries from the BCG World Atlas 6 and complemented the database in respect to dates of initiation of BCG vaccination. Data of COVID-19 cases and death per country were obtained from Google crisis response map as latest as till March 21st, 2020.
The countries were divided in three categories: low income (L) with an annual income of 1,025 dollars or less, lower middle income with an income between 1,026 and 3,995 dollars, and middle high and high income countries, which included countries with annual incomes over 3,996 dollars.
“In order to determine if BCG vaccination was protective for COVID-19 infections, we used the number of deaths per million inhabitants per country attributed to COVID-19. Most of the countries with low-income levels (17/18) reported zero deaths attributed to COVID-19 and have universal BCG policies in place consistent with a protective role of BCG vaccination,” the study revealed.
It added that middle high and high- income countries that have a current universal BCG policy (55 countries) had 0.78± 0.40 deaths per million people.
“In contrast, middle high and high income countries that never had a universal BCG policy (5 countries) had a larger mortality rate, with 16.39 ± 7.33 deaths per million people. This difference between countries was highly significant,” it stated.
Corroborating the study, Australia, Netherlands, Germany and the United Kingdom have announced they will begin large-scale human trials to see whether BCG vaccination protects health workers from Covid-19 by triggering an immune response to reduce symptoms, prevent severe illness or prevent infection.
Australia announced on Friday that it will begin BCG vaccine trials with around 4,000 physicians and nurses, who are at higher risk of becoming infected with the respiratory disease than the general population, and in older persons, who are at higher risk of serious illness.
Netherlands has recruited around 1,000 healthcare workers in eight Dutch hospitals to either receive the BCG vaccine or a placebo.