Oxford vaccine setback: What happens now?

It could be months or even a year before a clinical investigation decides whether trials of the Oxford University AstraZeneca COVID-19 vaccine can resume, experts have warned.

The vaccine was the leading candidate and expected to be rolled out to health workers and high-risk people from late this year, so the halting of the trial is a major setback that could dramatically delay a return to normal life.

It is standard practice to halt a clinical trial when a patient involved suffers a serious adverse event that leaves them hospitalised.

While the vaccine may not be at fault, the trial must be halted while a team of clinicians investigates.


AstraZeneca and Oxford University have not released details of the adverse event that halted the trial.

"In large trials, illnesses will happen by chance but must be independently reviewed to check this carefully. We are working to expedite the review of the single event to minimise any potential impact on the trial timeline," AstraZeneca said in a statement.

Flinders University Professor Nikolai Petrovsky, who is working on his own COVID-19 vaccine, said to halt a clinical trial the adverse event would have to be serious, such as the death of a patient or a life-threatening illness.


There were early warning signs of potential problems with the Oxford University's COVID-19 vaccine when nearly one in five patients developed a fever in early trials.

Vaccine experts have told News Corp this rate of fever in trial subjects is higher than normal for a vaccine and could present potential problems.

"A certain percentage of people will have epileptic tendencies and a fever could trigger convulsions and they could die," Prof Petrovsky said.

"The warning signs were always there. It's technology that has never been used before, but it was rushed and this is the inevitable consequence of governments and politicians driving vaccine development," he said.

The vaccine technology being used by Oxford University has never been used in a mass vaccination program before so there were always risks, he said.

Nucleus Network Principal investigator Paul Griffin, who is trialling the Novavax, University of Queensland and Serum Institute of India COVID-19 vaccines, agreed the fever rate for the Oxford vaccine was high but said it appeared to be managed by giving people paracetamol before the vaccine.

"It is a setback but just how significant it is hard to say at this stage," he said.

"I've been in situations where people have fallen down a cliff and we've had to put a hold on the study to ensure it's not related," he said.

There are currently over 165 COVID-19 vaccines in development, and the setback underlines the importance of funding a wide array of vaccine technologies.


Prime Minister Scott Morrison toured the AstraZeneca laboratories in Australia last month. Picture: Nick Moir/Getty
Prime Minister Scott Morrison toured the AstraZeneca laboratories in Australia last month. Picture: Nick Moir/Getty

There are three vaccines under development in Australia, but the federal government is only providing full financial support to one - the University of Queensland's molecular clamp vaccine.

Prof Petrovsky's company has developed a protein-based vaccine against COVID-19, but it has been granted only $1 million from the government, w which he says is nowhere near enough to run the phase 2 clinical trials needed to progress to the next stage.

He says Australia's vaccine manufacturer CSL is reluctant to work with his company Vaxine because it fears it could become a rival vaccine manufacturer in Australia.

The University of Queensland does not pose any such threat, he said.

AstraZeneca has refused to answer News Corp's questions about the timing of the event that halted the trial.

Prime Minister Scott Morrison announced on the weekend a $1.7 billion deal to secure 34 million doses of the AstraZeneca vaccine.

It is unclear whether the event that halted the trial occurred before that deal took place and whether the federal government was informed before signing off on the vaccine purchase.

Originally published as Oxford vaccine setback: What happens now?