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Six hundred Victorians are being sought for a trial investigating the long-term immune responses to a fourth COVID-19 vaccine dose.  

The Coalition for Epidemic Preparedness Innovations (CEPI) is funding this study that will help to inform the question regarding future COVID-19 booster strategies. Murdoch Children’s Research Institute was chosen to lead the trial because of its proven track record in conducting rigorous vaccine trials both in Australia and internationally.

Participants aged 18 years and older in Victoria, who have not received a fourth dose of the COVID-19 vaccine are being recruited. Volunteers will be randomised to receive either a Moderna (bivalent) or Novavax vaccine or alternatively can choose to be in a group of people who do not receive this additional dose but will still find out their antibody levels as part of the trial’s immune analysis.

All Victorian participants will be reimbursed to attend a clinic at the Murdoch Children’s in Parkville to provide up to four blood samples over the course of 12 months.

As part of the trial, participants will find out their COVID-19 antibody levels at their first visit, at 28 days (if they are in a vaccine group), at six months and at 12 months. Antibody levels are used to determine immunity against COVID-19. The trial will monitor how antibodies change over time and how this differs in the control and vaccine groups and in participants who have been infected with COVID-19. The trial will also measure T cells which are important for protection against severe disease.

Trial lead, Murdoch Children’s Professor Kim Mulholland, said the findings would include crucial immune data on the advantages of boosting people with a particular type of COVID-19 vaccine, which would then guide ongoing vaccination and boosting strategies.

“All countries are struggling with the issue of how to avoid repeated cycles of COVID-19 infection,” he said. "It is important to reduce the number of infections to prevent severe disease and to reduce the risk of long COVID.

“Our trial will specifically examine which vaccine booster type provides the best long-term immunity. The longer immunity lasts, the fewer boosters people will need, which would reduce ongoing financial burden on governments. People would also experience less of the common side effects, improving booster take-up.”

In Australia, the trial will include healthy young people aged 18-30 years as well as older participants.

CEPI has provided funding for this trial led by the Murdoch Children’s with support from the global non-profit organisation PATH. In line with CEPI’s access policy, access to the trial data will be shared through open-access publications and via scientific meetings to ensure all can benefit from the research findings.

Find out more on the trial or email  today.

Available for interview

Professor Kim Mulholland, Murdoch Children’s Group Leader, New Vaccines

Media Contact

Murdoch Children's Research Institute
Phone: +61 457 365 848

About Murdoch Children's Research Institute

Murdoch Children's Research Institute is the largest child health research institute in Australia committed to making discoveries and developing treatments to improve child and adolescent health in Australia and around the world. They are pioneering new treatments, trialling better vaccines and improving ways of diagnosing and helping sick babies, children and adolescents. It is one of the only research institutes in Australia to offer genetic testing to find answers for families of children with previously undiagnosed conditions.


The project and another two studies in Mongolia and Indonesia are funded by the Coalition for Epidemic Preparedness Innovations (CEPI).