Australian Prime Minister Scott Morrison
Australian Prime Minister Scott Morrison

An Australian-produced coronavirus vaccine candidate has been scrapped after trial participants returned false positive test results for HIV, developers announced Friday.

The inoculation, which had yet to progress beyond Phase 1 trials, was being jointly developed by the University of Queensland and Australian biotech company CSL.

Australia had hoped the vaccine would be available by mid-2021.

In a statement, CSL said no serious adverse effects had been reported in the 216 trial participants, and the vaccine was shown to have a “strong safety profile.” However trial data revealed that antibodies generated by the vaccine interfered with HIV diagnosis and led to false positives on some HIV tests, CSL said.

If the vaccine was rolled out nationally, CSL said it could undermine public health in Australia by causing a wave of false positive HIV tests in the community.

“Follow-up tests confirmed that there is no HIV virus present, just a false positive on certain HIV tests. There is no possibility the vaccine causes infection,” the statement added.

Australian Prime Minister Scott Morrison told reporters Friday that the vaccine “will no longer feature as part of the country’s vaccine plan.” Australia had pre-emptively ordered 51 million doses of the CSL vaccine in October.

Morrison said Australia had backed four vaccines that showed promise but “at no stage … believed that all four of those vaccines would likely get through that process.”

Read more about the vaccine here.