EXPERT REACTION: Preliminary results from University of Queensland's phase I COVID-19 vaccine trial

I have some reservations as to the likely effectiveness of the Pfizer vaccine, where the active component is encapsulated viral positive-stranded m-RNA. After removal of the capsule following injection, would not the viral RNA that constitutes the active ingredient of the vaccine be subject to degradation by the myriad of RNAses present in the the tissues following injection? Also, I believe that the need for continuous storage of the vaccine at -70C will rule out its use in much of the developing world.

Would not similar considerations apply to the UQ vaccine after separation of the DNA-RNA hybrid that constitutes the active component of the vaccine, or am I missing something?

For what it is worth, I believe that a live cold-adapted (ca) attenuated infectious bronchitis virus (IBV) coronavirus with spike antigens similar to COVID-19 and administered as an intra-nasal spray may have been a simpler approach. Live attenuated influenza vaccines are used extensively mainly for paediatric use in the US, the UK and Russia but not Australia. IBV, like influenza A and B viruses, grows to high titre in the allantoic cavity of 10-11 day-old chicken embryos, and similar titres can be achieved as for the manufacture of most influenza vaccines using the existing technology.

Preliminary data indicating that the University of Queensland’s vaccine appears to be safe is promising, but it’s too soon to say with certainty that the vaccine is both safe and effective. It is certainly encouraging that so far, data shows the vaccine is safe and well-tolerated when given. It is also extremely positive to hear that it has produced the desired antibody result. However, it is important to note that these are phase one results only, with limited preliminary data available to assess. So it’s promising, but it’s just the first hurdle.

It is always welcome news to hear potential COVID-19 vaccines are showing early positive signs. The results of UQ’s phase one trials are yet to be published in a peer-reviewed journal, but initial results showing a positive antibody response are heartening.

UQ’s vaccine candidate will soon commence phase 3 clinical trials, which will study its safety and efficacy in a large population in an area with high circulation of the virus. It’s important to remember there is still some way to go before the potential vaccine can be deemed safe and effective for the general population. We still need to await phase 3 clinical trial results and regulatory approval — from the Therapeutic Goods Administration, in the case of Australia.

Ultimately, we want to have as many safe and effective vaccines available, especially where different vaccines may be more suitable for different segments of the population, such as the elderly.

The report of a successful Phase 1 trial of the University of Queensland’s COVID-19 trial is welcome news. The new “molecular-clamp” vaccine binds together synthetic surface proteins from the SAR-COV-2 virus into a form that appears to generate a strong antibody response. Importantly, the antibody response also seems to work in elderly people. However, we will need to see the results of the Phase 3 trial which should be available in the latter half of next year to establish the vaccine’s efficacy, effectiveness, and safety. Pfizer have not disclosed how many elderly people or those who are immunocompromised are in their Phase 3 trial, so there is a query about how effective or safe their messenger RNA vaccine is in these groups. However, we do know that they have recruited a cohort in the 65-85 year-old range, and should be providing effectiveness and safety data for this cohort in the next few weeks.

The University of Queensland vaccine trial with its protein subunit vaccine appears to be progressing well. A protein subunit vaccine is a tried and tested vaccine technology, which can be effective. Adding into this mix UQ's novel clamp technology puts them in a strong position amongst the other vaccine candidates.

As Australians. we should be proud of their work so far. The production of a strong immune response to the vaccine in the elderly in the Phase 1 study is very pleasing because the elderly are vulnerable to severe COVID-19 and have a waning immune system that doesn't reliably respond to vaccines. However, these positive Phase 1 results don't automatically mean that the vaccine will remain as effective when conducting large Phase 3 trials where large numbers of vaccinated participants are pitted against the virus in the real world.

In other words, all these results mean is that the vaccine is functioning well enough at this early stage of testing to give researchers confidence to proceed to the next level of testing. But this can occur with a quiet level of confidence.

Excellent news about the Phase I trial for the University of Queensland COVID-19 vaccine, said to be showing a good safety profile and activating both arms of the immune response, antibodies and T cells, equivalent to that induced by an infection with coronavirus. We need to activate both these arms of the immune response to have some confidence the immune response will be long lasting. Additionally, if cytotoxic 'killer' T cells are also being activated, this could also potentially help eliminate viral reservoirs, by killing infected cells.   
 
Even better news is that similar immune responses are obtained in older and young adults, as older individuals are more difficult to vaccinate effectively, as their immune system is different. Since the University of Queensland’s vaccine’s ability to do this is likely due to the use of an adjuvant mixed into the vaccine, which has already been widely used in influenza vaccines in older adults, we have an additional layer of confidence in its predicted safety down the line in the context of the coronavirus vaccine.     
 
Producing the vaccine in Australia by CSL seems to be well on track. Really looking forwards to seeing the results of the next stages of human trials for this vaccine.

The UQ vaccine study is a phase 1, randomised, double-blind, placebo-controlled study to evaluate the safety and immunogenicity of an adjuvanted SARS-CoV-2 S clamp protein subunit vaccine in healthy adults aged 18 to 55 years old and in those aged 56 years and over. As recorded on the ClinicalTrials.gov website, the plan was to recruit 216 participants.

The media reports today quote Minister Hunt as saying that the vaccine is showing “strong safety and strong outcomes in terms of T cell and antibody” responses. The specific details of the safety and immune responses by age will be needed before definitive statements can be made. Of note, the Pfizer phase 1 vaccine trial, with an mRNA vaccine, showed that older participants 65-85 years had slightly less systemic reactions than younger participants, however this needs to be assessed along with immune response data by age to get a more complete picture.

Ultimately the performance, both safety and immunologic, will be needed to determine which vaccine works best for different groups in our communities.

The announcement by Pfizer & BioNTech of a vaccine estimated to be effective at 90 percent was great news. It indicates that vaccines are likely to work against COVID. We should expect more of such announcements to follow and the news coming from the University of Queensland is really encouraging.

While Pfizer is ahead in the development of its vaccine, there will be space for many companies in the production of vaccines. Having an Australian vaccine presents important benefits. Pfizer & BioNTech’s vaccine requires it to be stored at very low temperatures (-80 degrees) and people need two injections to be immunised. This is due to the innovative technology adopted by Pfizer and BioNTech.

UQ’s vaccine does not face these constraints and will therefore be easier to distribute. Most importantly, at a time where vaccine production will likely reach full capacity in 2021, having a vaccine in Australia will ensure that Australians will not suffer shortages because of world demand.