Australia halted development of a vaccine candidate for COVID-19 on Friday as several participants in early-stage trials generated antibodies to HIV after receiving the therapeutic potential.
No serious adverse events or safety concerns were reported in the 216 participants in 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, according to a statement.
However, the data showed that some patients developed antibodies against fragments of an HIV protein (gp41), which was used to stabilize the vaccine, he said.
After consulting with the Australian government, UQ and CSL decided not to advance the candidate vaccine to phase 2 and 3 clinical trials.
The vaccine was one of four candidates that Australia had committed to purchasing, and consequently deals were made to secure 51 million doses of the experimental vaccine.
UQ said that the trial participants were fully informed of the possibility of a partial immune response to this protein component, yet it was unexpected that the induced antibody levels would interfere with certain HIV tests.
The university said there is no possibility of the vaccine causing infection and routine follow-up tests confirmed that the HIV virus is not present.
The decision was made after the manufacturers consulted with experts who resolved the “implications” this problem presents for the vaccine’s implementation in broad populations, he said.
Reacting to the announcement, Australian Prime Minister Scott Morrison said abandoning the trial should show Australians that the government and researchers were proceeding with care.
“What happened today is not a surprise to the government. We are moving fast but not too fast,” he said, adding that the system is working as it should and Australians are protected, as always.
The University of Queensland began the phase 1 trial of v451 in July 2020 to evaluate its safety and immunogenicity in healthy volunteers.
He said the candidate vaccine has been shown to elicit a robust response to the new coronavirus and has a strong safety profile.
However, significant changes to well-established HIV testing procedures in the healthcare setting would be needed to accommodate the launch of this vaccine, according to the statement.
Although manufacturers have dropped more trials, the university said the phase 1 trial will continue to assess how long anti-HIV antibodies persist, adding that studies so far show levels are already declining.
The University of Queensland also plans to submit the full data for publication for peer review.
UQ vaccine co-director Professor Paul Young said that while the vaccine could be redesigned, the team did not have the luxury of time.
“Doing so would delay development for another 12 months or more, and while it’s a difficult decision to make, the urgent need for a vaccine should be everyone’s priority,” Young said.
“I said at the beginning of the vaccine development that there were no guarantees, but what is really encouraging is that the core technology approach that we use has passed the main clinical test. It is a safe and well-tolerated vaccine, which produces the strong virus- neutralizing effect we expected to see, “he said.
Andrew Nash, CSL chief scientist, noted that this result highlights the risk of failure associated with early vaccine development and the rigorous evaluation involved in making decisions about the advancement of discoveries.
In reaction to the announcement, Sanjaya Senanayake, Infectious Diseases Specialist and Associate Professor of Medicine at the Australian National University, said that while it is disappointing that an Australian vaccine candidate has been removed from the table, it is not surprising that one of many COVID-19 vaccines have failed.
“Overall, about 90 percent of vaccines never make it to market. As a global community, we have been spoiled by the unprecedented speed and success with which the development of COVID-19 vaccines has taken place,” he said Senannayake.
Diego Silva, from Sydney Health Ethics at the University of Sydney School of Public Health, noted that while the development might seem contradictory, from a research ethics point of view, it is a success.
“Science cannot consist solely of producing positive results; negative results will and must occur. Negative results are also as important as success in science, since they too form part of the evidence base for future research.” Silva said.
“The UQ researchers did the right thing by prioritizing the safety of the participants and the robustness of the science by stopping when they did,” he added.
(This story has not been edited by NDTV staff and is automatically generated from a syndicated feed.)