Mice have shown promising immune responses to a tuberculosis vaccine that's been repurposed to defeat COVID-19.
Australian researchers are heartened by animal trials that indicate their potential vaccine is prompting all the right responses to fight off the virus.
They've combined an existing tuberculosis vaccine with components of the SARS-CoV-2 virus, which is the pathogen that causes the COVID-19 disease.
Early results show treated mice produced high levels of specific antibodies that fight SARS-CoV-2 and help eliminate it from the body.
The potential vaccine also triggered a strong anti-viral response by T cells, a type of immune cell that searches out and destroys invaders.
Both of these responses are thought to be important to clear the SARS-CoV-2 virus.
In more good news, preliminary data suggests BCG:CoVac doesn't create high levels of inflammatory responses, which is a common problem in the development of new vaccines.
Lead investigator Professor Jamie Triccas, from the University of Sydney, says the tuberculosis vaccine has been adapted to deliver proteins from the SARS-CoV-2 virus surface.
The goal is for the human immune system to develop a "memory" of SARS-CoV-2 and develop immunity.
"BCG:CoVac is making the type of immune response that we predict is needed to control SARS-CoV-2 infection in humans," Prof Triccas said on Friday.
"We are currently determining how well the antibodies generated after vaccination can 'block' the virus from infecting cells and thus provide protection from disease".
The candidate vaccine is the work of the University of Sydney and Australia's medical research centre, the Centenary Institute.
They'll now work to determine how long the immune response lasts in treated mice.
Human clinical trials can't proceed until researchers can be sure the candidate vaccine is producing the right responses in animals.
Australian Associated Press