Melbourne-Made COVID-19 Vaccines Ready for the Next Step

The first six participants in the clinical trial of two Melbourne-made COVID-19 vaccines have been safely administered their doses, a significant moment in the development of the new vaccine candidates.

The two vaccine candidates were created by researchers at the Peter Doherty Institute for Infection and Immunity (Doherty Institute) and Monash Institute of Pharmaceutical Sciences (MIPS) and are distinct from existing vaccines in use around the globe.

‘It has been incredible to see the potential of mRNA vaccines over the last two years, and now Australia�s first mRNA vaccine has reached this milestone.’

These vaccines focus the immune response on the tip of the SARS-CoV-2 spike protein, called the receptor-binding domain (RBD). The RBD enables the virus to enter and infect cells in the body and elicits over 90 percent of neutralizing antibodies (antibodies that can block the virus) following COVID-19 infection.

What are the Two Candidates?

Doherty RBD protein vaccine - uses part of the virus protein, rather than genetic material or another virus, to elicit an immune response.

MIPS RBD mRNA vaccine - represents the virus genetic sequence that codes for the tip of the spike, which will lead to the production of the RBD protein.

In addition, they are �proof-of-principle' variant vaccines that present the Beta variant to the immune system, which was of the greatest concern when these vaccines were designed.

Furthermore, the Beta variant has two of the same key RBD mutations as the Omicron variants (BA.1 and BA.2), so they may also improve immunity to Omicron.

Are These Vaccines Safe?

The study is the first time a side-by-side comparison will be undertaken of protein and mRNA-based COVID-19 vaccine platforms, each vaccine at three dose levels (lower, intermediate, and higher doses).

It will assess the safety and efficacy of a single dose of these vaccines as a fourth dose of a COVID-19 vaccine, with all participants already having received their third dose of an existing vaccine at least three months prior.

These first six participants were assessed at the Royal Melbourne Hospital and then randomized to receive either the RBD protein vaccine, RBD mRNA vaccine, or a placebo.

Only after all 114 participants have been vaccinated and provided a blood sample 30 days post-vaccination will we receive the data and be able to begin analyzing how the vaccines have performed.

Getting to this stage has been an enormous team effort across both institutes, and we look forward to seeing how the vaccines perform in the clinic.

Next-generation vaccines will be an important tool to combat new variants as they arise and to help bring the global pandemic under control.

This trial is unique in that it's the first time a side-by-side comparison will be undertaken of two new COVID-19 platforms and so it is uncertain how long the trial will take to complete.

Volunteers are still being recruited and the trial is open to any healthy individual aged 18 to 64 living in Victoria, who has received their third dose of a COVID-19 vaccine at least three months ago.

People who have been infected with COVID-19 are also eligible provided they had their infection at least three months prior and have had their third vaccine dose.



Source: Medindia