A second generation of the University of Queensland's vaccine technology that was abandoned during the rush to develop an effective COVID-19 shot will move into human trials early next year.
UQ scientists were devastated in late 2020 when they had to drop out of the initial race to develop a COVID-19 vaccine after recipients in an early human trial of their molecular clamp technology falsely tested positive to HIV.
But they are hopeful a new generation of the molecular clamp – dubbed Clamp2 – will be used to produce future vaccines and save lives without concerns about false positive HIV tests.
The Coalition for Epidemic Preparedness Innovations (CEPI) has pledged up to $8.5 million to support further development of Clamp2 for use in the global response to future disease outbreaks.
UQ molecular virologist Keith Chappell said a "proof of concept" human trial of a Clamp2 vaccine against SARS-CoV-2, the virus that causes COVID-19, was due to begin in Brisbane next March.
"We never lost our belief that this was a technology that was needed to create vaccines and save lives," Associate Professor Chappell said.
"It's been a rollercoaster ride. We're riding high again and feeling really excited about what's to come."
Professor Chappell said 35 volunteers would be given a Clamp2 COVID vaccine and 35 would receive Novavax to compare the UQ technology against an already approved COVID-19 shot.
"We believe, and we've shown in animal studies, that Clamp2 is just as safe and effective as the first vaccine we tested in clinical trials," he said.
"Everything we've done has been comparing the original with the new platform. It has performed equivalent or better across every virus we've tested, and there is no evidence of any diagnostic interference with HIV tests."
Other viruses in their sights
The original clamp technology used in UQ's first experimental COVID vaccine contained two fragments of a protein found in HIV, which acted like a chemical bulldog clip, holding together an engineered version of the spike protein found on the surface of the SARS-CoV-2 virus.
That allowed the immune system to recognise – and attack – the spike protein, producing protective antibodies.
On its own, the SARS-CoV-2 spike protein is unstable. It needs to be locked into shape to ensure the vaccine produces a robust immune response.
Professor Chappell said he was unable to reveal details of Clamp2, due to intellectual property concerns.
But he said: "We can guarantee that there's no induction of cross reactivity to HIV diagnostics".
Although Clamp2 will first be tested in human trials of a SARS-CoV-2 vaccine, Professor Chappell said the scientists were not planning on adding to the COVID-19 vaccines already on the market at this stage.
"We selected SARS-CoV-2 not because we think a new vaccine is needed," he said.
"The vaccines that are out there are incredibly effective, especially if you've had multiple boosters, the level of protection is great.
"But putting our technology up against the best vaccines that are available and approved for use, we can tell with some certainty that our vaccine works."
Professor Chappell said the UQ team would instead look at using Clamp2 to develop vaccines against other viruses.
"This technology could be used for making better vaccines for viruses we already know about or for viruses against which there is currently no vaccine available and we're actively pursuing both of those areas," he said.
"There are viruses out there such as HTLV-1, which is a big problem in our Indigenous community in Australia, that we're actively looking to pursue and seeing if our vaccine could be effective for those sorts of diseases that aren't on the radar of big pharmaceutical companies."
CEPI's executive director of vaccine research and development, Melanie Saville, said the UQ team had demonstrated true grit and the power of scientific process to yield tangible advances in vaccinology.
"The second-generation molecular clamp vaccine technology that UQ have developed could provide the world with an additional tool to rapidly respond to future pandemic threats," she said.
As part of the university's partnership agreement with CEPI, UQ has agreed that vaccines produced using Clamp2 will be available in an outbreak situation to at-risk populations.
The batch of the Clamp2 SARS-CoV-2 vaccine needed for next year's human trial has been manufactured in Brisbane at a National Biologics Facility, housed within UQ's Australian Institute for Bioengineering and Nanotechnology.
