Coronavirus: fewer deaths seen in countries with mandatory tuberculosis vaccinations

A new study has found a correlation between countries that require citizens to get the TB vaccine and those with fewer cases and deaths

The vaccine is believed to sensitise the immune system in such a way that it is better able to respond to a coronavirus pathogen attack

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A child receives a vaccination from a health worker in the Philippines last year. Photo: AFP

Published: 4:00pm, 2 Apr 2020Updated: 4:00pm, 2 Apr 2020

Countries with mandatory policies to vaccinate against tuberculosis register fewer coronavirus deaths than countries that do not have such policies, a new study has found.

The preliminary study posted on medRxiv, a site for unpublished medical research, finds a correlation between countries that require citizens to get the bacillus Calmette-Guerin (BCG) vaccine and those showing fewer number of confirmed cases and deaths from Covid-19. Though only a correlation, clinicians in at least six countries are running trials that involve giving frontline health workers and elderly people the BCG vaccine to see whether it can indeed provide some level of protection against the new coronavirus.

Gonzalo Otazu, assistant professor at the New York Institute of Technology and lead author of the study, started working on the analysis after noticing the low number of cases in Japan. The country had reported some of the earliest confirmed cases of coronavirus outside China and it hadn’t instituted lockdown measures like so many other countries have done.

Otazu said he knew about studies showing the BCG vaccine provided protection against not just tuberculosis bacteria but also other types of contagions. So his team put together the data on what countries had universal BCG vaccine policies and when they were put in place. They then compared the number of confirmed cases and deaths from Covid-19 to find a strong correlation.

Japan has not yet instituted the strict lockdown measures seen in other countries. Photo: Bloomberg

Among high-income countries showing large number of Covid-19 cases, the US and Italy recommend BCG vaccines but only for people who might be at risk, whereas Germany, Spain, France, Iran and the UK used to have BCG vaccine policies but ended them years to decades ago. China, where the pandemic began, has a BCG vaccine policy but it wasn’t adhered to very well before 1976, Otazu said. Countries including Japan and South Korea, which appear to have managed to control the disease, have universal BCG vaccine policies. Data on confirmed cases from low-income countries was considered not reliable enough to make a strong judgment.

With nearly 900,000 cases and 45,000 deaths, the world is struggling to control Covid-19. Any vaccine for the disease is more than a year away from being available and the effectiveness of drugs under trial won’t be known for months to come. That’s why it’s reasonable to look at whether BCG vaccine could provide protection against Covid-19, said Eleanor Fish, professor at the University of Toronto’s immunology department. Otazu’s study is yet to undergo review by peers, a strict criteria for science studies.