CSIRO’s experts, Dr Rob Grenfell and Dr Trevor Drew comment on the news.
Dr Rob Grenfell, CSIRO’s Health and Biosecurity Director
Preliminary reports on Oxford University’s phase 1/2 trials showed promising results and a strong initial immune response. It is welcome news that Australians will have access to the vaccine should it prove successful.
CSIRO has been working with the Coalition of Epidemic Preparedness Innovations (CEPI) since the start of the pandemic to conduct preclinical evaluation of Oxford’s vaccine candidate. The early data that we’ve shared with CEPI and Oxford has enabled the university to commence its phase 3 trials.
While this news is encouraging it’s important to remember there are still hurdles to cross before we have a viable vaccine for COVID-19, including the outcomes of phase 3.
These are larger studies involving many thousands of volunteers in a current disease outbreak site- in this case South Africa, Brazil and Europe - that will tell us if the vaccine candidate is efficacious and safe for the broader population.
Dr Trevor Drew, Director, CSIRO’s Australian Centre for Disease Preparedness (ACDP)
Dr Drew is a member of a science advisory panel for the Australian Government to provide high-level scientific advice on COVID-19 vaccines.
Oxford University’s vaccine candidate is what’s known as a viral vector vaccine, meaning it is made from a non-replicating version of a common cold virus, an adenovirus. Oxford’s scientists have inserted the SARS-CoV-2 genome into a defective adenovirus, which can begin an infection in human cells but cannot replicate to develop the infection. The key coronavirus protein becomes expressed when the adenovirus starts to replicate. The immune system recognises the virus and develops immunity to the SARS CoV-2 virus.
Because it goes through the initial stages of replication, vaccines of this type are very stimulating to all parts of the immune system, compared to killed vaccines or those which only contain proteins of SARS-CoV-2.
As part of our preclinical study of Oxford’s candidate at the Australian Centre for Disease Preparedness, we are evaluating different administration methods of the vaccine to determine whether an injection or nasal spray confers better protection.
More than 2000 samples are currently being analysed by the team as part of the study. 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.