by Duncan Murray
SYDNEY, May 5 (Xinhua) -- A trial into the effectiveness of an existing tuberculosis (TB) vaccine in protecting against COVID-19 will expand to include frontline health workers in Australia, Spain and the Netherlands.
The Australian organization behind the study, Murdoch Children's Research Institute (MCRI) in Melbourne, said on Tuesday that the BRACE trial of the Bacille Calmette-Guerin (BCG) vaccine would be expanding from 2,500 people in Australia alone, to over 10,000 frontline workers in Europe as well.
Nigel Curtis, who is leading the trial, told Xinhua that the BCG vaccine had been shown to boost the body's immune system in a way that was "non-specific" to just one form of virus or bacteria, meaning that it may provide protection against COVID-19.
Invented in France over 100 years ago, the BCG vaccine is currently used in over 130 million babies each year to protect against TB, and according to the MCRI it has been shown in past trials to boost immunity against respiratory viral infections.
"The interesting thing about this vaccine is that over and above its ability to protect against TB, it has the ability to enhance the immune system," Curtis explained.
Curtis who heads MCRI's Infectious Diseases Research Group is a professor of the Paediatric Infectious Diseases at the University of Melbourne and head of the Infectious Diseases at the Royal Children's Hospital Melbourne.
He hopes that the BCG vaccine will prove effective in protecting healthcare workers exposed to COVID-19 against developing more severe symptoms and act as a "bridge" until a disease-specific vaccine can be developed.
"We now understand that this vaccine can strengthen the frontline part of the immune system, which is called innate immunity and this is the first part of the immune system that deals with viruses and other pathogens," Curtis said.
"The benefit of this vaccine is that it's been around for so long, we know it's safe so far, we know how to manufacture it and we could upscale production and use it."
While global interest into the effects of BCG and it's potential for use against COVID-19 has recently piqued, health authorities including the World Health Organization (WHO) have been quick to point out that due to a lack of clinical trials, there was no evidence that it offers any protection against the virus.
"There is experimental evidence from both animal and human studies that the BCG vaccine has non-specific effects on the immune system. These effects have not been well characterized and their clinical relevance is unknown," the WHO said in a statement last month.
At the time the WHO said that BCG should not be used against COVID-19, at the risk of depleting supplies of the drug used for neonatal vaccination in countries with high instances of TB.
"BCG vaccination prevents severe forms of tuberculosis in children and diversion of local supplies may result in neonates not being vaccinated, resulting in an increase of disease and deaths from tuberculosis," the WHO said.
The BRACE trial, led by Curtis, was one of two clinical trials identified globally by the WHO, saying that it would evaluate their evidence when it became available.
Thanks in part to a 10-million-Australian dollar (6.5-million-U.S. dollar) grant from the Bill and Melinda Gates foundation, the team from MCRI will collaborate with their colleagues in Spain and the Netherlands to test BCG's effects at the current heart of the pandemic.
"We're expanding the study to Europe, because there are more cases at the moment, that'll enable us to get a faster result," Curtis said.
"We'll be recruiting healthcare workers who are likely to come into contact with patients with COVID-19. So that's not just hospital doctors and nurses, but also potentially paramedics and ambulance drivers."
Curtis said that thanks to philanthropic support such as that of the Gates Foundation, the MCRI have been able to get the BRACE study off the ground extremely fast for a trial of its size, and hopefully start bridging the gap as the global search for a specific COVID-19 vaccine continues. Enditem