Australia has cancelled the production of a locally made Covid-19 vaccine after trial volunteers falsely tested positive for HIV, meaning the drug could interfere with diagnosis of that virus. Antibodies generated by the jabs developed by the University of Queensland (UQ) and biotech firm CSL led to trial subjects wrongly testing positive for the virus that causes AIDS. Further trials have been stopped. Scientists said the results were a blow to Australia’s vaccine development and was likely to force the country to buy more doses of imported shots. “While this is a tough decision to take, the urgent need for a vaccine has to be everyone’s priority,” said UQ professor Paul Young. Australia has ordered a total of 140 million shots from different suppliers, to inoculate its 25 million people, making it one of the most highly stocked countries in the world. “We want to ensure that Australians … have full confidence, absolute full confidence that when it gets the tick, they can get the jab, and they can make that decision for themselves and for their families, confidently,” said Scott Morrison, prime minister. Prof Sarah Palmer, from the faculty of medicine at the University of Sydney, said: “Sadly, this is a set-back for the development of Covid-19 vaccines. Generating a false positive for HIV is entirely unexpected for this vaccine, but underscores the critical necessity of testing the safety of newly-developed vaccines in large numbers of volunteers.” She said the Australian government, which was a major backer of the UQ vaccine effort, would have to consider funding other alternatives, including imported vaccine from firms such as Pfizer and Moderna.” Australia’s strict quarantine regime has seen the country quash earlier outbreaks and its tally of 28,000 infections is far fewer than in many other developed countries Its success in keeping a lid on infections has meant the country is not racing to start vaccinations like countries in Europe and jabs are not scheduled to begin until March. CSL, had been under a contract to produce 51 million doses of the UQ vaccine, and will instead produce an extra 20 million doses of the Oxford vaccine being developed with Britain’s AstraZeneca.