UK approves first-of-its-kind study to infect young people with Covid

New research aims to help doctors and scientists to further understand how immune system reacts to Sars-CoV-2

The UK has approved a first-of-its-kind study that will expose young and healthy volunteers to Covid-19 as part of efforts to further understand the virus, the government has announced.

Due to begin in the next few weeks, the study will recruit up to 90 carefully-selected participants aged between 18 and 30 – who are at the lowest risk of complications from coronavirus – and expose them to the pathogen in a safe and controlled environment.

The researchers will initially use the coronavirus that was first introduced to the UK in March 2020, as opposed to the more transmissible variant that was detected in Kent late last year.

After exposure, the volunteers will be closely monitored by medics and scientists for 24 hours a day throughout the study. They will be kept in quarantine for a minimum of 17 days and only allowed to return home after this period once they are no longer deemed infectious.

It’s hoped the research, which has received £33.6m in government funding, will help doctors to further understand how the immune system reacts to Sars-CoV-2, identify factors that influence how the virus is transmitted and aid the development of treatments and vaccines.

Known as a Human Challenge study, the first phase of research aims to establish the smallest amount of virus needed to cause infection. Scientists expect this take up to two months.

Once completed – and depending on the outcomes – additional volunteers will then be recruited, vaccinated and exposed to the virus to help identify the most effective jabs and accelerate their development. Approval for this part of the study has not yet been granted.

Scientists may also later move on to expose volunteers to the different variants that have emerged across the globe.

The trial is not designed to induce symptoms in volunteers and as soon as people start to shed virus from their nose, they will be given remdesivir as a pre-emptive treatment.

The Human Challenge study is being delivered by a partnership between the government’s Vaccines Taskforce, Imperial College London, the Royal Free London NHS Foundation Trust and the clinical company hVIVO.

It will be conducted at the Royal Free Hospital’s specialist and secure clinical research facilities in London, which are specifically designed to contain the virus and prevent it from being spread beyond the volunteers.

Participants will only be allowed to leave the study and return home once they are no longer deemed infectious.

The researchers are working closely with the Royal Free Hospital and the North Central London (NCL) Adult Critical Care Network to ensure the study will not affect the NHS's ability to care for patients during the pandemic.

The study will not begin without their go-ahead, the Department for Business, Energy and Industrial Strategy (Beis) has said.

Commenting on the new study, business secretary Kwasi Kwarteng said: “While there has been very positive progress in vaccine development, we want to find the best and most effective vaccines for use over the longer term.

“These Human Challenge studies will take place here in the UK and will help accelerate scientists’ knowledge of how coronavirus affects people and could eventually further the rapid development of vaccines.”

Peter Openshaw, a professor of experimental medicine at Imperial College London who is involved in the study, explained that one of the main reasons for conducting the research is that it offers “the fastest way to evaluate novel vaccines”.

Speaking at a media briefing on Wednesday, he said: “In the future we won’t have a large number of people to do [vaccine trial] studies in the field. A Human Challenge study allows you to vaccinate volunteers and then infect them in a controlled way with the virus, to compare perhaps new vaccines with first-generation vaccines.

“Human Challenge also allows you to answer critical questions about the vaccine themselves, what is the best dosing interval, what is the best dose to give people to protect them against active infection, and when do you need to revaccinate people.”

“Other things you can do is provide a platform to investigate new treatments … and also test efficient diagnostic systems.”

Dr Chris Chiu, from Imperial College London and the chief investigator of the study, called on young and healthy volunteers who have not been infected before to come forward and “join this research endeavour”.

“Our eventual aim is to establish which vaccines and treatments work best in beating this disease, but we need volunteers to support us in this work,” he added.

Dr Chiu added that the study also offers an opportunity to “learn about the biology of Sars-CoV-2”.

“We don’t know actually much about transmission of this virus, what role young, healthy and relatively asymptomatic people have in shedding virus,” he said.

“Do they shed a lot when they have not many symptoms or do they shed a little? All of that is somewhat inferred from what we see in the population. But we don’t have very clear data on that. Irrespective of the strain we use, these are the fundamental questions which are going to have major public impact.”

The virus being used in the research has been produced by a team at Great Ormond Street Hospital, in collaboration with virologists at Imperial College London.

Volunteers in the study, which will involve 12 months of follow-ups, as well as treatment if needed, will receive roughly £88 a day in compensation. This will amount to £4,500 if the participants remain in the study for the entire year.

These Human Challenge studies have been implemented before to accelerate the development of treatments for a number of diseases, including malaria, typhoid, cholera, norovirus and flu.

The trials have also helped researchers establish which possible vaccine is most likely to succeed in phase three clinical trials that would follow, usually involving thousands of volunteers.

The Health Research Authority (HRA) and the Medicines and Healthcare products Regulatory Agency (MHRA) are the UK's regulators responsible for providing ethics and regulatory approval, respectively for all human clinical trials.

Research Ethics Committees (RECs) are formed by the HRA as part of the approval process.

A specially appointed independent REC has approved the study, and after reviewing the protocol, the MHRA concluded the virus characterisation study did not require its approval because the study does not involve an investigational medicinal product.

Dr Charlie Weller, head of vaccines at the Wellcome Trust, said approval for “this research is a very encouraging and important step.”

“As with any human infection study, there are clear ethical considerations,” he added. “The safety of volunteers is paramount and the regulatory approval will have been through the highest level of assessment.”

However, professor Stephen Griffin, a virologist at the University of Leeds, warned that the study is “using a more virulent agent compared to many that have gone before”.

“Whilst we understand a great deal about the risk factors associated with severe Covid-19, it is not always clear why certain patients progress whilst others do not,” he said. “It is also notable that even mild Sars-CoV-2 can cause longer-term morbidity in a proportion of patients across all age groups, even following relatively mild infection.”