As It Happens

Oxford researchers facing pressure to find COVID-19 vaccine as human trials continue

Oxford researchers are enrolling thousands of people in human trials for their potential COVID-19 vaccine, and the principal investigator says he's never been under so much pressure to perform.

'There's never been as much interest in what we're doing,’ professor Adrian Hill says

A laboratory technician fills a syringe with a COVID-19 vaccine candidate ready for trial on monkeys at the National Primate Research Centre of Thailand. (Mladen Antonov/AFP/Getty Images)
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Transcript

Oxford researchers are enrolling thousands of people in human trials for their potential COVID-19 vaccine, and the principal investigator says he's never been under so much pressure to perform.

"There's never been as much interest in what we're doing, and I think the pressure is attenuated by the fact that there are so many vaccine programs," Adrian Hill, professor of human genetics and director of the Jenner Institute at Oxford University, told As It Happens host Carol Off. 

This pressure comes as the school's research into the desperately needed vaccine ramps up its testing and aims to administer 10,000 doses over the next few weeks.

In a press release Friday, Oxford University said it had already given the potential vaccine to 1,000 adult volunteer as part of its Phase 1 trial watch for adverse reactions and make sure the product is safe.  

Now the researchers are entering Phase 2 trials, in which they will expand the testing age range to include a small number of older adults and children. After that, Phase 3 will assess how the vaccine works in a large number of people over the age of 18.

The Oxford vaccine is just one of dozens in development around the world. The first human vaccine trials began in March, just two months after scientists identified COVID-19, the disease caused by the coronavirus currently sweeping the globe. 

During the 2003 SARS epidemic, it took 20 months for a potential vaccine to get to the stage where it was ready for human testing —although the vaccine was never developed, as the epidemic was over by then.

As of May 15, the World Health Organization reported that there were 110 candidate vaccines in pre-clinical evaluation around the world, and eight in human Phase 1 and Phase 2 trials.

A different Phase 1 trial has been approved by Health Canada to take place in Halifax.

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Adult participants in the Oxford trial are randomized to receive one or two doses of either the potential COVID-19 vaccine or a control vaccine used to immunize against meningitis, according to the university press release. 

"What we do is compare the number of cases of COVID in the people who got the irrelevant vaccine, which hopefully would be higher than those who got the COVID vaccine," Hill said. 

Prior to the human trials, researchers conducted safety tests on monkeys, which were deliberately infected with the virus.

The animals were vaccinated, and then a month later given "a really high dose of the virus" to check that there wasn't any evidence of damage being done, Hill said.  

Adrian Hill, professor of human genetics and director of the Jenner Institute at Oxford University, said vaccine trails on monkeys have shown 'almost complete protection' against the virus. (Mladen Antonov/AFP/Getty Images)

"What we found was that in the lungs, there was really almost complete protection, no evidence of disease," he said. "All the monkeys were fine."

What couldn't be interpreted from this study is how the vaccine will handle a "normal dose" of the virus, like what someone might catch from sitting next to an infected person on a bus.  

"We don't know whether the vaccine will work really well against preventing the spread of the virus," Hill said. "We will be planning to do some further animal tests with a ... normal challenge dose. But nobody knows yet." 

Distributing vaccine logistically 'daunting'

Once a vaccine is found, Hill says "the real challenge" is how logistically "daunting" it will be to make enough doses for everybody who will want it — particularly if he and his team are the first to finish. 

"We're not talking millions of doses; we're talking of billions," he said. 

Hill says he's hopeful that by September there will "not be huge numbers, but maybe a million, maybe more" vaccine doses ready.  

"[If] everything goes as planned, you should have over a billion doses in the next 12 months. [But] it's hard to estimate as you scale up whether you also get the same yields that you get on a small scale. But it's certainly going to be a lot," he said. 

While the pressure may be mounting, Hill's message to those who are concerned about the science being rushed is that while the Oxford COVID-19 vaccine may be new, the adenovirus-type vaccine that underpins it has been tested in "many tens of thousands of people."

"It's not just that we will have tens of thousands of people vaccinated with the COVID vaccine by October," he said.

"It's that you're building on that previous safety, based on databases from using this type of vaccine safely for other [illnesses]."


Written by Adam Jacobson. Produced by Katie Geleff. With files from Emily Chung.

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