UK plans to infect healthy volunteers in COVID-19 research trials

Controversial ‘human challenge’ technique aims to study the disease and potentially speed up vaccine development, but there are ethical and safety concerns.

Human challenge studies are typically used to test vaccines against mild infections [File: Kirsty Wigglesworth/AP]

Researchers in the United Kingdom are preparing to infect healthy young volunteers with the coronavirus that causes COVID-19, becoming the first scientists to use the controversial technique to study the disease and potentially speed up the development of a vaccine that could help end the pandemic.

The UK government said on Tuesday that it will invest 33.6 million British pounds ($43.5m) in the Human Challenge Programme in partnership with Imperial College London, laboratory and trial services company hVIVO, and the Royal Free London NHS Foundation Trust.

If approved by regulators and an ethics committee, the studies will start in January with results expected by May 2021, the government said.

Using controlled doses of the virus, the aim of the research team will initially be to discover the smallest amount of virus it takes to cause COVID-19 infection in small groups of healthy young people, aged between 18 and 30, who are at the lowest risk of harm, the scientists leading the studies said in a statement.

Up to 90 volunteers could be involved at the initial stages, they said, and the virus to be used will be manufactured in labs at London’s Great Ormond Street Hospital.

“Deliberately infecting volunteers with a known human pathogen is never undertaken lightly,″ said Peter Openshaw, co-investigator of the research.

“However, such studies are enormously informative about a disease, even one so well studied as COVID-19.”

Tens of thousands of volunteers around the world have already signed up to participate in more traditional trials of COVID-19 vaccines. Critics of human challenge studies question the need to expose healthy people to the virus when the disease remains widespread and vaccine development is moving quickly.

A spokeswoman for the World Health Organization (WHO) said there are “very important ethical considerations” when approaching human challenge trials.

“What is critical is that if people are considering this, it must be overseen by an ethics committee and the volunteers must have full consent. And they must select the volunteers in order to minimise their risk, because you will be challenging people with a virus that we do not have a treatment for,” Margaret Harris, the WHO spokeswoman, told reporters in Geneva.


Human challenge studies are typically used to test vaccines against mild infections to avoid exposing volunteers to a serious illness if the vaccine does not work.

Such trials have been previously used to develop vaccines for diseases including typhoid, cholera and malaria.

Governments around the world are funding efforts to develop vaccines in hopes of ending the coronavirus pandemic that has pummelled the international economy, shutting businesses and putting millions of people out of work.

Globally, 1.12 million people have died from the virus and more than 40.5 million have been infected.

Forty-six potential vaccines are already in human testing, with 11 of them in late-stage trials — and several expected to report results later this year or in early 2021.

Chris Chiu, an Imperial College scientist involved in the challenge trial, said his team’s “number one priority is the safety of the volunteers”.

“No study is completely risk-free, but [we] will be working hard to ensure we make the risks as low as we possibly can,” he said.

But Jonathan Ball, professor of molecular virology at the University of Nottingham, warned safety concerns may limit what researchers can learn from the study.

“Any studies involving the novel coronavirus will focus on those most likely to experience a mild infection – young healthy volunteers,” he said in a statement from the Science Media Centre.

“Yet the people we need to protect against serious disease are more vulnerable elderly people, so what we learn from challenge studies might have limited wider relevance.”

The UK’s hVIVO, a unit of pharmaceutical services company Open Orphan, said last week it was carrying out preliminary work for the trials.

Source: News Agencies