Prof Hill said his team was making preparations for a challenge trial within months.
“We’re hoping to be doing challenge trials by the end of the year,” he told The Guardian. “This might be in parallel or might be after the phase three trial is completed. They’re not competing options, they’re complementary.”
Sir John Bell, the Regius Chair of Medicine at Oxford University, who is also working on the vaccine, said new drugs including remdesivir would help ensure the safety of challenge trial volunteers.
“I think some of the new neutralising therapies look pretty good, so if somebody ever got sick, you could fix it,” he told The Telegraph. “I suspect the challenge study will be in the mid-autumn. That would be my bet.”
The development came as more than 100 prominent scientists, including Prof Hill and 15 Nobel Laureates, signed an open letter to Dr. Francis Collins, the head of the National Institutes of Health (NIH) in the US, that said challenge trials could “greatly accelerate” the development of a Covid-19 vaccine.
“If challenge trials can safely and effectively speed the vaccine development process, then there is a formidable presumption in favour of their use, which would require a very compelling ethical justification to overcome,” the letter published by 1 Day Sooner, an organisation that advocates for challenge trials, said.