A coronavirus vaccine trial by University of Oxford researchers aims to get efficacy results by September, and manufacturing is already underway.
A team led by Sarah Gilbert, a professor of vaccinology, has recruited 500 volunteers from the ages of 18 to 55 for the early- and mid-stage randomized controlled trial. It will be extended to older adults and then to a final stage trial of 5,000 people. Gilbert said that the timing is ambitious but achievable.
“We would hope to have at least some doses that are ready to be used by September,” she said in an interview. “There won’t be enough for everywhere by then, but the more manufacturing we can do starting from now, then the more doses there will be.”
Volunteers to take part in the trial have been abundant, she said, and it’s no longer accepting new subjects.
Gilbert, whose research on vaccines began at the University of Oxford in 1994, was awarded a £2.2 million ($2.8 million) grant from the UK’s National Institute for Health Research and UK Research and Innovation in March to scale up her team’s efforts to move into Covid-19 vaccine research.
The group’s experimental immunization is among the first to enter clinical trials. The World Health Organization counts 70 vaccine candidates in development, with three others in human testing. They are from CanSino Biological Inc. and the Beijing Institute of Biotechnology; Inovio Pharmaceuticals Inc.; and Moderna Inc. along with the National Institute of Allergy and Infectious Diseases.
Gilbert’s trial divides 510 participants into five groups that will be observed for about six months with the option for a follow-up visit about a year after entering the trial. One group will receive a second intramuscular shot of the vaccine four weeks after the initial immunization.
The research aims to determine the efficacy, safety and immunogenicity of the candidate vaccine, named ChAdOx1 nCoV-19. A vaccine against meningococcal disease will be given to participants who will be randomly chosen for control purposes.
ChAdOx1 nCoV-19 is a so-called recombinant viral vector vaccine. It’s made from a harmless virus that’s been altered to produce the surface spike protein of the pandemic-causing SARS-CoV-2 virus.
The vaccine acts by priming the immune system to recognize and attack the coronavirus, stimulating a T-cell response. It uses the same technology as a shot Gilbert’s team previously developed for the related MERS coronavirus. That vaccine appeared to be safe in animal and early-stage human testing, giving confidence for the coronavirus version.
“We’re doing safety testing,” Gilbert said, “but we’re not concerned.”
Gilbert’s team has used the same technology for about 10 different vaccines, she said. The challenge that now arises is testing the vaccine even as virus infection rates vary.
“It’s going to be complicated trying to determine vaccine efficacy when the virus transmission in different places is going up and then going down again,” she said. “The trial has to be set up in the right place at the right time and that’s very hard to predict. That’s why we’re planning to do multiple trials in multiple countries.”
Another hurdle is money.
“We have some funding but we don’t have all of it yet,” she said. “You can’t just go and start manufacturing at large scale. You have to put a lot of things in place and that’s what we’re trying to do at the moment. It’s in the order of tens of millions of pounds.”
The WHO is creating a forum for everyone developing Covid-19 vaccines to share their plans and initial findings, according to Gilbert.
“Work is continuing at a very fast pace,” she told the Lancet medical journal, “and I am in no doubt that we will see an unprecedented spirit of collaboration and cooperation, convened by WHO, as we move towards a shared global goal of Covid-19 prevention through vaccination.”