The world’s first Covid-19 human challenge study in the UK has received ethics approval from the country’s research ethics committee (REC).

With the ethics approval secured, the Covid-19 human challenge study – the protocol for which was developed by Open Orphan’s hVIVO for the UK Government – could begin within a month in Covid-19 secure facilities at the Royal London NHS Foundation Trust.

The study is being supported by Imperial College London and the UK’s Vaccine Taskforce. It aims to recruit up to 90 healthy volunteers aged between 18 and 30.

hVIVO chief scientific officer Dr Andrew Catchpole told Pharmaceutical Technology there are four safety mitigations associated with the study. The first is “volunteer eligibility: only those at the lowest possible risk of severe disease will be eligible”, while the second is “only a very  small , minimal amount of highly controlled virus will be used to inoculate the volunteers”.

Third, “very early administration of antivirals will be given at the onset of infection as a pre-emptive intervention therapy as a precautionary measure for the first groups of volunteers” and finally “we will ensure very close medical monitoring throughout the trial and for year-long follow up visits”.

The virus that will be used in the study was produced by Great Ormond Street Hospital in collaboration with Imperial College London. This is the initial strain of the virus, which emerged in March 2020, as it is believed to present low risk to young, healthy adults. There are too many unknown factors associated with the emerging variants of SARS-CoV-2.

The aim of the study is to enable greater understanding of how the immune system reacts to Covid-19, as well as how the virus is transmitted.

In the future, the researchers plan to also administer vaccine candidates that have been deemed to be safe in other clinical trials to the volunteers. This will help to identify the most effective vaccines by comparing them side-by-side. It is hard to study the efficacy of vaccines as those in traditional trials may not be naturally exposed to the virus, whereas human challenge studies deliberately infect volunteers with Covid-19.

REC ethics approval is required for protocols for all trials being carried out in the UK. The committee is made up of up to 15 individuals who are not involved in the trial and they consider the aims of the trial, the risk-benefit ratio to participants and the qualifications and expertise of the team running the trial.

Catchpole said: “The main benefits are that this allows us to test new vaccines that are required to deal with the new variations of Covid-19, ie. the second generation of vaccines which will be required later this year or early next.

“Another advantage of a controlled human challenge study is that it allows the doctors and medics to get a much better understanding of Covid-19 and its progression through the body from the earliest moment of infection.

“This first study will also give us significant insight into asymptomatic infection, which is very common in this age group and is virtually impossible to study by other means.

“As we move to vaccine testing we can then get direct evidence on if the vaccine can prevent asymptomatic infection and therefore have a major impact on transmission.”

Imperial College London’s Dr Chris Chiu, the study’s chief investigator, said: “The recent worsening of the pandemic and urgent need to vaccinate people quickly and effectively have raised new questions about Covid-19 and how to best protect ourselves against it.”

Wellcome head of vaccines Dr Charlie Weller said: “The safety of volunteers is paramount and the regulatory approval will have been through the highest level of assessment.

“Given that current treatment options for Covid-19 are limited, it is important that volunteers are being sourced from the lowest-risk groups and are closely monitored throughout the course of the study.”

Human challenge studies have previously been used effectively for other public health threats. “hVIVO has been successfully undertaking challenge studies since 2001 and we have run challenges successfully for a range of infectious diseases and respiratory diseases, that includes Respiratory Syncytial virus, asthma…influenza, COPD, and many others,” said Catchpole.  “We are currently working on new challenge models for not just Covid-19 but also malaria, pneumoccolus, norovirus, and new influenza models and a range of other challenge models.”