Australia's largest biotechnology company CSL (ASX: CSL) has abandoned its collaboration with the University of Queensland to develop a promising COVID-19 vaccine after discovering it gives a false positive diagnosis for HIV.
While the move does not impact CSL's leading role in the fight against COVID-19 nationally, it wipes out 10 months' work by scientist from both camps to develop their own vaccine.
While CSL says the decision will not impact the company's FY21 profit guidance, shares in the company opened more than 2 per cent lower today.
The vaccine had proven effective during Phase 1 trials conducted in July without any serious adverse effects or safety concerns reported among the 216 participants in the trial. CSL says the vaccine had a robust response towards the virus.
However, tests were abandoned when it was discovered they gave participants a false diagnosis of HIV.
The CSL vaccine produced antibodies that were directed towards the "molecular clamp" component of the vaccine which caused the false HIV readings in some tests.
Follow-up testing showed HIV was not present in those trial participants and that the vaccine itself did not cause HIV.
"This outcome highlights the risk of failure associated with early vaccine development, and the rigorous assessment involved in making decisions as to what discoveries advance," says CSL's chief scientific officer Dr Andrew Nash.
"This project has only been made possible by the innovative science developed by world-class scientists at The University of Queensland and the strong collaboration between our organisations, and many others, over the last 10 months."
Nash says CSL through its Seqirus flu vaccine subsidiary it will continue its efforts to fight COVID-19 through other previously announced relationships, including its deal to produce the Oxford/AstraZeneca vaccine.
"Manufacture of approximately 30 million doses of the Oxford/AstraZeneca vaccine candidate is under way, with first doses planned for release to Australia early next year," Nash says.
"In addition, CSL has agreed at the request of the Australian Government to manufacture an additional 20 million doses."
A successful outcome from the UQ trials would have led to the large-scale manufacture of this additional vaccine.
While it is possible to re-engineer the vaccine, UQ vaccine co-lead Professor Paul Young says time is not on their side.
"Doing so would set back development by another 12 or so months, and while this is tough decision to take, the urgent need for a vaccine has to be everyone's priority," he says.
"I said at the start of vaccine development that there are no guarantees, but what is really encouraging is that the core technology approach we used has passed the major clinical test.
"It is a safe and well-tolerated vaccine, producing the strong virus neutralising effect that we were hoping to see."
Young says the team plans to undertake further work on the "molecular clamp" technology as a pathway to vaccines for future biosecurity threats.
Updated at 10.25am AEDT on 11 December 2020.