Professor Young said the team, which had been working on the vaccine for the past 11 months, was “devastated” but he stressed that was the reason clinical trials were done.
“It’s particularly tough on a day not far in advance of when we were going to announce what great phase-one data we had, which was that the vaccine was shown to be safe and extremely well tolerated and induced an antibody response in excess of what is seen in recovered patients,” he said.
“We only heard about 24 hours ago of the decision to pull funding, a decision made by CSL and the federal government together.”
Professor Young said the past 24 hours had been hard on the team but the scientists knew when starting the project there was a chance it might not work.
“In science, things don’t always go right. I think in possibly my first interview I said there’s no guarantee – well, we’ve come to that point now,” he said.
Up to 500 people were working on the UQ vaccine.
Every trial participant who was given the live vaccine and not a placebo generated a small immune response to HIV because the molecular clamp that held the viral protein together was derived from a fragment of HIV, a protein called Gp41.
The clamp does not affect how well the vaccine works and people are not contracting HIV, but because the fragment is recognised by the body’s immune system, it generates some antibodies.
These antibodies are looked for in many HIV screening programs now in place, and no good workaround could be found.
Professor Munro, who had been overseeing the transition of the vaccine from laboratory to manufacturing, said they first became aware of the issue “some weeks ago” and had been trying to find a way around it.
“What we’ve been doing is working with [experts] to figure out, ‘What’s the potential impact of this? Is this something that’s going to present a real challenge?’ ” he said.
In the past few days, the decision was made that changing HIV testing algorithms was a significant barrier.
“CSL had to make a decision this week whether to submit files for that global regulatory study, so the decision had to be made fairly quickly,” he said.
Professor Munro said everyone who participated in the trial had been contacted and informed about what was going on.
Some had already stopped registering an HIV response, with all of them seeing declining figures over time.
Professor Chappell, who developed the molecular clamp technology, said in hindsight they might not have used the HIV fragment but they needed to move forward quickly with development.
“HIV is a well-studied virus. The structure of this protein has been known for some time … it’s a well-known structure,” he said.
“If we could go back in time, we’d make changes.”
Professor Chappell said they wanted to be as transparent about the process as possible so people remained confident about vaccines to fight COVID-19.
“Transparency from vaccine developers is of crucial importance, and I hope us being open and upfront about these results boosts public confidence in vaccines overall,” he said.
As the three scientists were talking, a group of about 50 people from the university, including several researchers who worked directly on the project, gathered behind the television cameras.
When the news conference ended, they broke into spontaneous applause, with the three men smiling sadly and thanking them, before moving back into the building.
Stuart Layt covers health, science and technology for the Brisbane Times. He was formerly the Queensland political reporter for AAP.