Scientists are currently cultivating the Delta Covid variant in laboratories with the goal of infecting volunteers on purpose.
British researchers are developing the samples that will be used in challenge trials, in which participants will be paid up to £4,500 for their participation.
In March, Imperial College London and the University of Oxford began two trials in London with the goal of developing new vaccines and treatments.
Under careful supervision, forty healthy young volunteers have already been exposed to the original Wuhan strain.
The next stage of the trials, however, will infect participants with Delta, the more transmissible strain that is now prevalent throughout the UK. According to Andrew Catchpole, the company’s chief scientific officer, challenge-trial partner hVivo and colleagues in the Netherlands have been growing the variant.
The variant, which is being grown from an original human sample, has proven more difficult to develop than the original Wuhan strain, according to Mr Catchpole, a virologist.
‘Delta has been more difficult,’ said Dr Catchpole. ‘Not all clinical samples grow as well in cell culture.’
However, researchers have nearly enough of it now to begin early-stage testing.
During the growing process, scientists ensure that the virus does not mutate in a way that differs from the naturally occurring variant. In the coming weeks, hVivo hopes to transport the Delta virus to London for further production in a second lab.
In challenge trials, healthy people are intentionally infected with viruses and then given a vaccine shot to see if the vaccine can clear the virus.
These studies have been conducted on a variety of illnesses, including malaria, typhoid, and the flu.
However, unlike those illnesses, there is no treatment that can keep someone from becoming seriously ill with Covid.
Because of the ethical implications, none of the 23 coronavirus vaccine clinical trials currently underway around the world have used the contentious research method. Instead, they are relying on community members who became infected by accident.
It hopes to have produced half a liter by November, with trials with the strain set to begin at the end of the year.
Dr. Garth Rapeport, a respiratory-viral infection specialist, said, ‘It’s not that different from making vaccines.’ It must be strictly monitored and regulated.’
He assisted in the initial setup of the trials and stated that the rapid spread of Delta has rendered the original strain being studied largely irrelevant.
Researchers are encouraging people between the ages of 18 and 30 who are at the lowest risk of becoming seriously ill with Covid to participate in the study. Trialists are only accepted if they have no prior history of Covid or symptoms, no underlying health conditions, and no known risk factors for the disease, such as being overweight or smoking.
Anyone interested in participating must undergo extensive screening, which includes blood tests, X-rays, heart scans, and physical examinations, to ensure they are not susceptible to Covid.
Researchers stated that they were only looking for the “healthiest” Brits.
After passing the tests, the volunteers were infected with the original strain of coronavirus that has been circulating in the UK since February of this year. They were kept under constant surveillance 24 hours a day, seven days a week. A collaboration between the No. 10 Vaccines Taskforce, Imperial College London, the Royal Free London NHS Foundation Trust, and drug researcher hVIVO is carrying out the challenge study.
The study’s initial goal will be to help doctors understand how the immune system reacts to different levels of coronavirus and how a Covid virus infected person transmits infectious particles into the environment.
However, it is hoped that vaccine candidates found to be safe in early studies will be tested on participants to expedite their approval. Vaccines are typically tested on two groups of people, one given the vaccine and the other as a control, both of whom must contract the disease naturally.
Traditional clinical trials necessitate tens of thousands of participants in order to increase the likelihood of some of them becoming infected with coronavirus in the community.
However, because everyone is guaranteed to be infected with the disease, the pool of volunteers in challenge trials can be much smaller.