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What are the concerns for people involved in now-abandoned Australia’s Covid vaccine trials?
The government had struck a deal with CSL Ltd to manufacture two potential coronavirus vaccines - one developed by Oxford University/AstraZeneca, and the other by CSL’s own labs in collaboration with the Univesity of Queensland.
Australia has hit a major roadblock in its attempt to secure millions of doses of a promising vaccine candidate against the coronavirus disease (Covid-19) after trial participants returned false HIV positive results. The Australian government had agreed to buy 51 million doses of Covid-19 vaccine developed by biotech firm CSL Ltd and the University of Queensland (UQ).
The government had struck a deal with CSL Ltd to manufacture two potential coronavirus vaccines - one developed by Oxford University and AstraZeneca, and the other by CSL’s own labs in collaboration with the UQ. However, CSL will not progress the vaccine candidate to Phase 2/3 clinical trials as the Phase 1 data showed the generation of antibodies that interfered with “certain HIV tests.”
What are the concerns for people involved in the trial?
CSL and the University of Columbia said in a joint statement that there is no possibility the vaccine causes infection, adding that the routine tests confirmed there is no HIV virus present. CSL stated that the generation of antibodies was directed towards fragments of a protein (gp41), which is a component used to stabilise the vaccine.
“Trial participants were fully informed of the possibility of a partial immune response to this component, but it was unexpected that the levels induced would interfere with certain HIV tests,” it added.
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What are the implications for vaccine rollout?
Australia had ordered 51 million dosed of the UQ/CSL vaccine and the firm was working towards Phase 2/3 clinical trial and large-scale manufacture of the vaccine. CSL and the Australian government have agreed to not proceed to Phase 2/3 trials. The government is increasing the purchase of the Oxford-AstraZeneca vaccine from 33.8 million doses to 53.8 million doses. The doses of the Novavax vaccine have also been increased from 40 million to 51 million.
How the researchers reacted?
Professor Paul Young, UQ vaccine co-lead, said that though there were no guarantees, the core technology approach used in the development of the vaccine has passed the major clinical test. Young added that it was possible to re-engineer the vaccine, but the team did not have the luxury of time needed.
“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 stated.
Dr Andrew Nash, chief scientific officer for CSL, said that the outcome highlights the risk of failure associated with early vaccine development. He also informed that CSL has agreed at the request of the Australian government to manufacture an additional 20 million doses of the Oxford-AstraZeneca vaccine candidate
