AUSTRALIA has today announced stoppage of further development of a COVID-19 vaccine candidate as several participants in the early-stage trials generated antibodies for HIV after receiving the potential therapeutic.
According to report, there were no serious adverse events or safety concerns reported in the 216 participants of the phase 1 trial of the v451 COVID-19 vaccine candidate being developed by the University of Queensland (UQ) in collaboration with biotech company CSL.
However, data showed that some patients developed antibodies towards fragments of a HIV protein (gp41), which was used to stabilise the vaccine, it said.
Following consultation with the Australian Government, UQ and CSL decided not to progress the vaccine candidate to phase 2 and 3 clinical trials.
The vaccine was one of four candidates that Australia had committed to buying and accordingly agreements were made to secure 51 million doses of the experimental vaccine.
In a statement, UQ said the trial participants were fully informed of the possibility of a partial immune response to this protein component; however, it was unexpected that the antibody levels induced would interfere with certain HIV tests.
The university said there is no possibility the vaccine causes infection, and routine follow up tests confirmed there is no HIV virus present.
The decision was taken after the makers consulted experts who worked out the ‘implications’ that the issue presents to rolling out the vaccine into broad populations, it said.
Reacting to the announcement, Australian Prime Minister Scott Morrison said abandoning the trial should show Australians, the government and researchers were proceeding carefully.
“What happened today is not a surprise to the government. We are moving swiftly but not with any undue haste,” he said.
He added that the system is working as it should and Australians are protected as always.
It will be recalled that the University of Queensland commenced the phase 1 trial of v451 in July 2020, to assess its safety and immunogenicity in healthy volunteers.
It said the vaccine candidate has shown that it elicits a robust response towards the novel coronavirus and has a strong safety profile.
Meanwhile, significant changes would need to be made to well-established HIV testing procedures in the healthcare setting to accommodate rollout of this vaccine, according to the statement.
Although the makers have abandoned further trials, the university said the phase 1 trial will continue to assess how long the HIV antibodies persist.
The University of Queensland also plans to submit the full data for peer review publication.
According to UQ vaccine co-lead, Professor Paul Young, although it was possible to re-engineer the vaccine, the team did not have the luxury of time needed.
Doing so would set back development by another 12 or more months and while this is a tough decision to take, the urgent need for a vaccine has to be everyone’s priority.” Young said.