Australia's CSL ends COVID-19 vaccine trial, to focus on AstraZeneca's shots

Australia's CSL Ltd abandoned further trials of a COVID-19 vaccine it was developing with the University of Queensland after some participants tested false positive for HIV in Phase 1 trials, the biotech giant said on Friday.

While there were no serious adverse effects seen in the Phase 1 trial of 216 participants, data showed antibodies that had developed interfered with HIV diagnosis and led to false positives on some HIV tests, CSL said. Given the results, CSL said it had come to a decision with the Australian government to stop Phase 2 and Phase 3 trials of the vaccine.

"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," said Andrew Nash, CSL's chief scientific officer. CSL, however, agreed to make another 20 million doses of AstraZeneca and Oxford University's vaccine, on top of the 30 million doses already underway at the request of the government. The first doses are expected in Australia early next year.

"I said at the start of vaccine development, that there are no guarantees," University of Queensland's vaccine co-lead, Paul Young, said in a statement released by CSL. The company said Phase 1 trials of the vaccine would continue and further data analysis would be submitted for peer review in the future.