The Phase 1 trial of COVAX-19^®, the Australian COVID-19 vaccine developed by Vaxine Pty Ltd, was independently conducted by the PARC clinical trial team, a University of Adelaide based research group. The study was started on June 30, 2020, at the Royal Adelaide Hospital and included 40 healthy participants aged between 18 and 65 years. Participants were randomised on a 3:1 ratio to receive two intramuscular doses 3 weeks apart of either active vaccine at a dose of 25µg spike protein plus 15mg Advax and 0.15mg CpG55.2 (30 participants) or saline placebo (10 participants).

The primary objective of this double-blinded randomised controlled study was to assess the safety and tolerability of the COVAX-19^® vaccine. Across all study participants, administration of either vaccine or placebo was well tolerated. All of the local reactions were graded as mild and did not require any medical intervention. The most frequent systemic adverse events were headache, fatigue, and muscle ache. No major adverse effects on hematology and biochemical results were seen. No serious adverse event was considered at least possibly related to vaccination in the study participants. Collectively, the COVAX-19^® vaccine was safe and well-tolerated in this study, with an acceptable rate of largely minor adverse reactions typically seen after immunisation. In the preclinical studies, the COVAX-19^® vaccine induced potent immune responses against the SARS-CoV-2 virus in mice, ferrets, and cynomolgus monkeys. The results of this Phase I human trial also confirmed the ability of COVAX-19^® to induce humoral and cellular immune responses.

Our COVAX-19^® vaccine is demonstrated to be safe, well-tolerated, and immunogenic in preclinical and clinical studies and can now move to a Phase 2/3 study. The Phase I study protocol is available on clinicaltrials.gov (identifier, NCT04453852) and detailed results will be published soon.