The great hope of Australia's vaccine strategy was the University of Queensland's "Molecular Clamp". Unfortunately the clamp molecule, derived from part of the AIDS virus, triggered false positives in AIDS tests. They used that particular molecule as it was available and time scales were tight. A revised version is being developed with a new clamp molecule, but it won't be ready for the current round of vaccinations.

https://www.abc.net.au/news/health/2021-04-26/university-que...