With expansive Covid-19 clinical plan in full gear, Oxford team reports positive animal data on adenovirus-based vaccine
A few days after the first UK volunteers were dosed with a Covid-19 vaccine developed at Oxford University’s Jenner Institute, the team said a crucial animal study has come back positive.
The preliminary results, first reported by the New York Times, mark the second positive experiment of a vaccine candidate involving rhesus macaque monkeys disclosed in recent days. China’s Sinovac posted promising data with its inactivated virus vaccine candidate on a preprint server last Monday. Notably, US biotech Moderna skipped the animal trials altogether before jumping into human trials, with the promise to run those studies in parallel.
Oxford’s clinical effort is notable for its scale. While other Phase I trials enrolled only dozens of participants, the UK trial — which had a control arm with a meningitis vaccine — had aimed for 1,100 volunteers and recruited the majority of them by the time they kicked off the trial last week.
“This is really important, because moving quickly to assess a vaccine efficacy while COVID infections are still common can provide valuable information regarding Correlates of Protection (CoPs),” Evercore ISI analyst Josh Schimmer wrote in a note, adding that “vaccines which can be administered as a single dose (potentially adenovirus vector ones) will have a key advantage since they need fewer vials. Jenner is also studying a 2-dose regimen.”
Dubbed ChAdOx1 nCoV-19, the vaccine uses a weakened version of an adenovirus that infects chimpanzees to carry genetic material that codes for the spike protein on the new coronavirus. The Jenner team, led by Sarah Gilbert, had employed the same approach to develop experimental vaccines against Ebola, MERS and malaria.
Scientists at the NIH’s Rocky Mountain Laboratory inoculated six monkeys with single doses of the vaccine last month. When “challenged” by heavy quantities of SARS-CoV-2, the primates stayed healthy on day 28, researcher Vincent Munster told the Times. He expects to share the results with other scientists within days.
Should the safety and efficacy signals be replicated in the human trial — and given the circumstances, a dozen infections on the placebo arm compared with only one or two on the vaccine arm would count as victory, according to Jenner Institute director Adrian Hill — Oxford is plotting a Phase II/III effort with 5,000 people next month.
All of that could culminate in an emergency approval in September, beating the 12- to 18-month timeline that seemed to have been the consensus (and would already be unprecedented). But other developers such as Moderna CEO Stéphane Bancel have similarly suggested that the earliest viable vaccines should be available by the fall — if only to the most at-risk populations.
On Monday the Oslo-based Coalition for Epidemic Preparedness Innovations, a major funder of multiple vaccine efforts, lent credence to the idea.
Richard Hatchett, the group’s head, noted that several vaccine candidates it’s backing may enter a second phase of testing as soon as late spring or the summer. Later in the day Moderna — the first US biotech to launch a Covid-19 vaccine trial — announced it’s filed an IND to begin Phase II.
Foreseeing potential issues with manufacturing, CEPI is setting up production facilities and distribution in every region. While it only has capacity for a few million doses in-house, the Oxford team said it’s working with “a half dozen” companies across Europe and Asia, including the Serum Institute of India, to potentially churn out billions of doses if it secures approval. No agreement, however, has been reached in North America.
“I personally don’t believe that in a time of pandemic there should be exclusive licenses,” Hill said. “So we are asking a lot of them. Nobody is going to make a lot of money off this.”
Social image: The first volunteer receives a jab of the Oxford vaccine. Credit: AP Images
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