LONDON – In the coming weeks a small, carefully selected group of volunteers is expected to arrive on the 11th floor of a London hospital to learn what the rest of the 7.8 billion people around the world have tried to avoid: coronavirus infection .
Tiny droplets of the virus are given into their noses as part of a plan approved by UK regulators on Wednesday to intentionally infect unvaccinated volunteers with the coronavirus.
The scientists hope to eventually expose vaccinated people to the virus to compare the effectiveness of different vaccines. Before doing so, however, the project’s supporters must expose unvaccinated volunteers to determine the lowest dose of the virus that will reliably infect them.
Up to 90 people could take part in the study, but the number could be fewer if researchers can determine the correct dose with fewer volunteers.
By controlling the amount of virus people are exposed to and monitoring it from the time they are infected, scientists hope to discover things about how the immune system reacts to the coronavirus that would be impossible outside of a laboratory – and devise ways to do it directly to infect comparing the effectiveness of treatments and vaccines.
“We will learn a lot about the immunology of the virus,” said Peter Openshaw, a professor at Imperial College London who was involved in the study, on Wednesday. He added that the study would be able to “not only accelerate understanding of diseases caused by infections, but also accelerate the discovery of new therapies and vaccines”.
The idea of such a study, dubbed the Human Challenge Challenge, has been hotly debated since the early months of the pandemic.
In the past, scientists have deliberately exposed volunteers to diseases such as typhoid and cholera to test vaccines. But infected people could be cured of these diseases. Covid-19 has no known cure, which puts the scientists responsible for the UK study into largely unknown ethical territory.
To ensure participants do not get seriously ill, the UK study will be limited to young, healthy volunteers aged 18 to 30 years.
But these types of patients also had severe Covid 19 cases, and the long-term consequences of an infection are also largely unknown. Age restrictions can also make it difficult to extrapolate the results to older adults or people with pre-existing medical conditions, whose immune responses may differ, and who are the target audience for treatments and vaccines.
“It will be a limited study,” said Ian Jones, professor of virology at the University of Reading, who is not part of the study. “And you could argue that, by definition, it won’t investigate those where it is most important to know what is going on.”
Currently the only part of the study that has been officially approved by UK regulators is the experiment to determine the lowest dose of virus needed to infect humans.
After exposure to the virus, participants will be isolated in hospital for two weeks. They will be paid £ 4,500, or about $ 6,200, for this one year worth of scheduled follow-up appointments. The researchers said this would compensate people for their absence from work or family without creating too much economic incentive for people to participate.
When the idea of human challenge experimentation first came out last year, some scientists saw it as a way to cut the crucial time in the race to identify a vaccine. Unlike large clinical trials where scientists wait for vaccinated people to encounter the virus in their communities, researchers in this project might infect people who were vaccinated on purpose.
With multiple vaccines approved, the goals of this human challenge study are slightly different.
For now, researchers will be exposing people to the version of the virus that has been spreading across the UK since last spring, rather than the contagious and potentially more deadly variant that has caught on more recently. But eventually, they said, they could give people experimental vaccines to combat the effects of new, more worrisome variants, and then expose them to those versions of the virus.
You could also directly compare different vaccine doses and dosing intervals for the same vaccine.
