The University of Queensland and biotech company CSL have pulled the plug on further trials of their COVID-19 vaccine after antibodies in the vaccine were found to interfere with HIV tests.
In a statement on Friday, CSL said that while the Phase 1 trial of the vaccine “has shown that it elicits a robust response towards the virus and has a strong safety profile”, the antibodies in the vaccine could return false positive HIV test results.
“There is no possibility the vaccine causes infection,” CSL said.
“It is generally agreed that significant changes would need to be made to well-established HIV testing procedures in the healthcare setting to accommodate rollout of this vaccine. Therefore, CSL and the Australian government have agreed vaccine development will not proceed to Phase 2/3 trials.”
Human trials of the vaccine began in July, with 216 Queenslanders having volunteered since then.
At a press conference, Department of Health secretary Brendan Murphy said the vaccine “was likely to work”, but it may have negatively impacted public perception.
“We knew that we didn’t want to have any issues with confidence, and this false-positive test may have caused some confusion and lack of confidence. But it was a very, very good technology. It was looking like it was going to make antibodies, and it probably would have worked very well as a vaccine. But we can’t have any issues with confidence,” he said.
Reengineering the vaccine would be possible if there were more time, according to UQ vaccine co-lead Professor Paul Young.
“Doing so would set back development by another 12 or so months, and while this is a tough decision to take, the urgent need for a vaccine has to be everyone’s priority,” he said.
CSL noted that the manufacture of approximately 30 million doses of the Oxford/AstraZeneca vaccine candidate was underway for Australia, and the organisation has agreed to manufacture an additional 20 million doses.
Prime Minister Scott Morrison said Australia’s share of the Novavax vaccine would also be upped from 40 million to 51 million doses.
“So that’s an extra 20 million doses of AstraZeneca, and an extra 11 million doses of Novavax. The AstraZeneca vaccines, of course, are manufactured here in Melbourne by CSL,” he told the press conference.
Morrison noted that while the government had initially identified four potential vaccines for Australia, “at no stage” did the commonwealth expect all four to be successful.
“If that had occurred, that would have been truly extraordinary, based on the process of vaccine development not only in this country, but anywhere else. So that’s why we spread our risk. That’s why we backed important projects. And that’s why we pre-prepared to ensure that we could deal with any issues along the way,” he said.