U.K. gets approval to infect healthy volunteers in world's first coronavirus 'challenge trial'

The effort, funded by the British government, aims to accelerate scientific understanding of vaccines and treatments.

The first stage will begin within the month and see up to 90 adults, aged 18 to 30, exposed to the coronavirus "in a safe and controlled environment" to gauge the smallest amount of virus needed to cause infection, the government said in a statement Wednesday.

The government has said that in subsequent stages, which will require further approval, it hopes to quickly assess vaccines and conduct head-to-head comparisons.

Infecting healthy people with a potentially deadly virus - even in small doses and controlled settings - is controversial. And some in Britain have questioned whether there's still a need, given the rapid authorization and rollout of highly effective vaccines. More than 15 million people in the United Kingdom have already received at least one "jab," as a vaccine shot is called here.

Clive Dix, the head of Britain's vaccine task force, said, "We have secured a number of safe and effective vaccines for the U.K., but it is essential that we continue to develop new vaccines and treatments for covid-19.

"We expect these studies to offer unique insights into how the virus works and help us understand which promising vaccines offer the best chance of preventing the infection."

Robert Read, a professor of infectious diseases at the University of Southampton, said the current vaccines, while very good against most of the strains circulating, "may not actually be the last vaccines that we use globally." The human challenge trials could "give ourselves the potential to test new vaccines very quickly, and that's really the primary purpose of this effort."

When the trial gets underway, volunteers will be infected via droplets squirted up the nose and then monitored closely during a hospital stay. In addition to regular blood and heart rate tests, patients will be given scratch-and-sniff cards, to detect loss of smell, and cognitive tests on a tablet, leader researcher Christopher Chiu said.

Peter Openshaw, an immunologist at Imperial College London and a co-investigator on the study, said it was "important to emphasize that the aim of the initial studies are not to produce any great severity of disease.

"Indeed, if we can just demonstrate that the virus grows in the nose, that's really the endpoint we're looking for.

"We're not aiming to make any of the subjects sick, and we're doing that by very slowly escalating the dose."

Scientists will use the version of the virus that has been in circulation since March of last year and not any of the more infectious variants.

The volunteers in the first study will receive about 4,500 pounds ($6,243) for their participation over the course of the study, which will involve 17 days of quarantining at the Royal Free Hospital in north London and follow-ups over 12 months.

The study "involves quite an imposition on a young person, 17 days in quarantine when you cannot be visited by any member of your family or friend or relative," said Terence Stephenson, chairman of the Health Research Authority. "For the first 1,500 pounds for 17 days, we've got something like 88 pounds a day, which I don't think anyone would sense was a ridiculous coercion or inducement."

Andrew Catchpole, chief scientific officer for hVIVO, a clinical research organization that is recruiting volunteers, said that while "thousands" have offered to participate, the study is still looking for recruits who have not yet been exposed to the virus and who can pass health screening tests.

Jacob Hopkins, 23, is hoping to take part in the trials, and he is waiting to hear back about his background health checks. "I'm not ignorant to the real risks, but I've gone through rigorous pre-screening, and the risks are very, very minor for someone who is young, fit and healthy," he said.

Hopkins said his biggest concern was the potential long-term effects, "but that's still not enough to make me change my mind. I want to help bring an end to this as soon as possible."