The University of Oxford has published a preliminary report on its vaccine candidate, ChAdOx1 nCoV-19, in The Lancet. CSIRO’s experts weigh in on the news.
Dr Rob Grenfell, CSIRO’s Health and Biosecurity Director
Preliminary findings from the Phase 1/2 trials of the University of Oxford’s vaccine candidates show encouraging results. The report shows the vaccine candidate generated an immune response, making antibodies and stimulating T-cells to fight COVID-19. We don’t know exactly know what protects us against a coronavirus infection, as there is still so much we don’t know, so our research continues.
While the race for a vaccine against this virus is moving quicker than we’ve ever seen before, and the global need for a vaccine is evident, we can never forget safety is still of the highest importance.
While these are hopeful results, there’s still a long way to go before we have a viable vaccine at our fingertips. We need to await the additional phase 3 clinical trials, that will study the potential vaccine candidate’s performance and safety. These larger studies are conducted in broader populations in current disease outbreak sites, in this case South Africa, Brazil and the UK. It won’t be clear if the vaccine candidate works, and is safe for the broader population, until these large-scale clinical trials are completed, and we can see through the randomized approach the vaccinated group is protected.
We also need to determine the best way to administer the vaccine. As part of CSIRO’s preclinical study of Oxford’s vaccine candidate, our scientists evaluated the efficacy of one versus two doses as well as administration of the vaccine via a nasal delivery and/or an intramuscular injection.
Dr Trevor Drew, Director, CSIRO’s Australian Centre for Disease Preparedness (ACDP)
CSIRO recently completed pre-clinical trials for two vaccine candidates, including Oxford’s ChAdOx1 nCoV-19, at ACDP, its high-containment facility in Geelong. These vaccine candidates were selected by the Coalition for Epidemic Preparedness Innovations (CEPI) in consultation with the World Health Organisation, based on principles behind their design, the quality of their development and their readiness for testing.
The pre-clinical testing at CSIRO started in March and involved obtaining and characterising SARS-CoV-2 – the causative virus of COVID-19 and establishing a ferret model in which to test vaccines. A cohort of ferrets were vaccinated and, following a number of weeks to allow their immunity to develop, challenged with the virus. Researchers then assessed the efficacy of the vaccine candidates by characterising the immune response of the animals to the vaccines and comparing the level of protection between vaccinated and unvaccinated ferrets, as well as the different delivery methods and single verses double doses.
Early data from these trials has been shared with the University of Oxford. The results from this study are currently going through internal and external review, quality assurance and a compliance audit. This is all part of the process of rigorously determining the safety and effectiveness of the vaccine candidate, to the standard required by licensing authorities. The results will be published following this review.