The Australian developers of a coronavirus vaccine candidate announced on Friday the project has ended after several trial participants falsely tested positive for HIV.
The vaccine candidate was being formulated by the University of Queensland and the Australian biotech company CSL, and was still in its Phase 1 trials. In a statement, CSL said none of the 216 trial participants reported experiencing any serious side effects, and while the vaccine was shown to have a "strong safety profile," the antibodies generated interfered with HIV diagnosis, leading to the false positives.
"Follow up tests confirmed that there is no HIV present, just a false positive on certain HIV tests," CSL said. "There is no possibility the vaccine causes infection."
The vaccine's "molecular clamp is made from a HIV protein, which on its own is harmless," Adam Taylor, a research leader in emergency viruses at Griffith University's Menzies Health Institute, explained to CNN. "The molecular clamp stabilizes the coronavirus spike protein and presents it to the body in a way that promotes a good immune response. This is why the clamp technology is so vital."
The Australian government had hoped that the University of Queensland and CSL vaccine would be available by mid-2021, and ordered 51 million doses of the vaccine. The country has already ordered 73.8 million doses of the AstraZeneca and Novavax vaccines, and Australian Minister for Health Greg Hunt said it now plans on ordering 31 million additional units from the companies.