BRACE COVID-19-Specific vaccine sub-study (BCOS)
With philanthropic support from the Bill & Melinda Gates Foundation, this is a sub-study to the Murdoch Children’s Research Institute’s trial of Bacille Calmette-Guérin (BCG) vaccine to reduce the impact of COVID-19. By recruiting existing BRACE trial participants for the sub-study, researchers are seeking answers to these key questions:
BCOS Australia and Brazil
Does BCG vaccination, by boosting the immune system, improve the response to Pfizer, AstraZeneca and CoronaVac?
BCOS Brazil
Is it possible to predict who remains susceptible to SARS-CoV-2 variants despite previous COVID-19 disease or COVID-19-specific vaccination?
Australian sub-study participants
- Are participants in the main BRACE trial
- Are healthcare workers at the Royal Children’s Hospital, Melbourne, Epworth HealthCare, Women's and Children's Hospital, Adelaide or the Royal Adelaide Hospital
- Had not had their COVID-19-specific vaccine at the time of enrolment
- Have not previously been diagnosed with COVID-19 at the time of enrolment
How it worked
BCOS participants attended one, two, or three vaccine sub-study clinic visits and provided a blood sample each time. The number of visits depended on the type of COVID-19-specific vaccine received. Where possible, we combined the visits with regular BRACE trial 3-monthly clinic visits.
Participants completed additional questionnaires a week after each vaccine sub-study clinic visit to tell us which COVID-19-specific vaccine they received and any reactions experienced.
Participation in the sub-study ended 28 days after receiving the second dose of a COVID-19-specific vaccine.
Learn more about BCOS

The global race to understand Covid-19 variants
Is it possible to predict who’s susceptible to SARS-CoV-2 variants – despite previous COVID-19 infection or vaccination?

ABC NewsRadio interview
Dr Nicole Messina, BRACE Biosample and Laboratory Lead, speaks on ABC NewsRadio about the BRACE COVID-19-Specific vaccine sub-study.