Vaccines and Antibodies

The Doherty Institute has been funded through the National Health and Medical Research Council (NHMRC) by the Medical Research Future Fund to conduct a unique Phase I study of two second generation COVID-19 variant vaccines. The safety and ability of the new vaccines to promote a protective immune response will be studied.

SARS-CoV-2, the virus that causes COVID-19, is enveloped by proteins that resemble spikes, which enable the virus to attach and enter cells in our bodies. This attachment is mediated by the tip of the spike protein, known as the receptor binding domain (RBD). Our vaccine candidates focus specifically on the RBD because if we can block this attachment we can block infection.

Since the onset of the global COVID-19 pandemic, several safe and effective vaccines have been developed and licensed worldwide. However, there is an important need for more vaccines against SARS-CoV-2 to ensure global supply.

This study is looking at two different vaccines for prevention of COVID-19 infection. Both locally made in Australia, the vaccines are a recombinant protein vaccine (similar to the Novavax vaccine) and an mRNA vaccine (similar to Pfizer or Moderna COVID-19 vaccines).

The vaccines in our trial use two very different approaches:

1. RBD protein – represents the tip of the spike to focus the immune response on this critical region of the virus targeted by antibodies that neutralise viral infectivity.
    
2. RBD mRNA – represents the virus genetic sequence that codes for the tip of the spike, which will lead to production of the RBD protein.

The protein vaccine candidate has been developed by scientists at the Doherty Institute, and the mRNA vaccine candidate by scientists from the Monash University Institute for Pharmaceutical Sciences.

This is the first time a side-by-side comparison will be undertaken of two COVID vaccines.

Recruitment for Phase 1 of the study is now finished. We would like to thank all the people in the community that volunteered to be part of this important study.