Challenge Studies: The volunteers offer to become infected with coronavirus

Would you agree that coronavirus stings your nose? All, in the name of science.

There are enough who would, and indeed campaign to be allowed to take part in so-called “challenge trials” to try to accelerate the development of a coronavirus vaccine.

Alastair Fraser-Urquhart is one of them. He is 18 and has just received his results at A level. Initially, he did not have the degrees he needed to study biomedicine for cancer at University College London, until the government’s U-turn.

Now that he’s done, he’s thinking of taking a year off, in part to work with 1 Day Sooner, a group campaigning for Covid vaccine trials.

“I’m in the lowest risk category for Covid, so why should I not make that choice and help save other people who would be treated much worse than me,” he says.

A challenge study would involve volunteers receiving a Covid vaccine, and being infected with live coronavirus a few weeks later to test whether the jab protected them. Those involved would be quarantined in a clinical examination unit for two weeks and kept under close medical supervision to see if they became infected and developed symptoms.

So what does Alastair’s family think? “It’s fair to say they were not there over the moon, but I did not have any major opposition. My father was absolutely not chuffed when I told him in June. Both my brothers are OK with that.”

How can challenge trials help?

The whole world is waiting for a Covid vaccine. There are now at least 30 experimental vaccines in human trials. Thousands of volunteers have been immunized. What happens next depends on where those volunteers live and how they behave. All are told to maintain social distance, and not to look for coronavirus.

That is good advice for two reasons: but half of the volunteers in tears will receive Covid vaccines, the rest will be a control group. Participants who do not currently know in which group they are. Second, the faxes may not work at all.

That’s in part why so many threads are being set up in coronavirus hotspot zones in Brazil and the United States, the two least affected countries in the world.

Trials with challenge would remove the element of chance and you would get immediate results.

I am the medical editor of the BBC. Since 2004, I have reported on an enormous range of topics, from cancer, genetics, malaria, and HIV, to the many important advances in medical science that have improved human health. I have also followed pandemic threats such as bird flu like Sars and Mers. Now I focus on Covid-19 and its enormous global impact.

What are we waiting for?

Not so fast. There are many people ready to take part in challenging studies. But there are good reasons why no one has sprinted to organize one.

Challenge trials have a long history. They have been used to test new vaccines against influenza, typhoid, cholera and malaria. Indeed, the first vaccine, developed by Dr. Edward Jenner in the late 18th century, involved what would now be considered a very double challenge trial involving the eight-year-old son of his gardener. Jenner had noticed that dairy farmers were immune to smallpox, a devastating viral infection, after suffering from chickenpox, a harmless virus. James Phipps was inoculated with cowpox blocks and was then intentionally exposed to smallpox but was not infected. Smallpox is the only infectious disease that has been destroyed from the planet.

Nowadays, there is usually a rescue kit on hand, in case volunteers fall ill after a trial with challenge of faxes. Knowing that there is an effective treatment means that the risks to volunteers are kept to a minimum. That is not the case with Covid-19. No medicine is guaranteed to prevent an infection from becoming serious, even life-threatening.

So what are the risks?

It is impossible to be precise about this. About nine in 10 deaths with Covid-19 have been in people with underlying health conditions. Studies cited by 1 Day Sooner suggest that the risk of death for healthy and unhealthy people in their 20s can range from 1 in 3,300 to 1 in 14,000. But almost all deaths in this age group are among people with underlying health conditions, so healthy individuals are at a lower risk. The statistical guru Prof David Spiegelhalter made a rough estimate for me and thinks, for healthy people in their 20s it could be as low as 1 in 40,000. He says it is about the same risk that they will be killed in a road accident every year.

Doesn’t that sound too risky?

It may not sound very dangerous, unless of course you are the one in 40,000 than what the actual figure is. But it gets more complicated. The risk may depend on how much coronavirus has been injected into the nose. Some studies have suggested a link between the high levels of exposure to viruses and the severity of disease. That a Goldilocks approach would be necessary – the volunteers of the challenge would need enough virus to infect them, but not so much that it could overwhelm their immune system. To work this out, you need a preliminary series of dose-escalation tests, where volunteers would have no protection at all.

Alastair Fraser-Urquhart is also ready to take part in those trials, saying he thought carefully about the risks. “What happens when I’m seriously ill? If I do, it will be for science and provide incredibly valuable data,” he says.

Sean McPartlin, 22, is another volunteer. From Ireland he holds a degree in philosophy and studies at Oxford.

“My mother has a hereditary lung disorder and every day we go without a vaccine is a day she takes a risk she doesn’t have to,” he says. “I want to do everything I can to help get that vaccine for her and everyone else like her as quickly as possible.”

Sean says his family has supported him. He thinks two weeks in a clinical research unit could help him concentrate on his studies, and the main threat would be boredom.

“Participating in a trial like this involves time and energy, and that’s something I’m happy about. I have no medical knowledge, so I can help in some other way.”

What is it like to be a test with a challenge?

Amy Letts, 36, has participated in studies to test vaccines against malaria and typhus. For the malaria test, she had to pretend to be bitten by several mosquitoes infected with the malaria parasite. For the other study, she drank a solution laced with typhoid bacteria.

“I had a mix of reasons to participate. First, there is the potential good it can do. I was happy when I found out that the typhoid vaccine I received was a success and is now being used. to save thousands from lives.

Then there is the compensation. They pay for your time. I lived very close to the research unit in Oxford, so it was easy for me to pop in and have my daily blood tests and checkups. “

Amy tried to get the volunteer to receive the Oxford Covid-19 vaccine, but was excluded because it uses the same technology – a chimpanzee adenovirus – as the malaria vaccine she received there a decade ago.

Will those tears for Covid ever challenge?

I think it’s likely, but they may not get along for months. The team behind the Oxford University / AstraZeneca Covid vaccine is apparently considering them.

Their vaccine is already in advanced research involving tens of thousands of volunteers. A challenge study could supplement this data, but it would not replace it.

Prof Adrian Hill, director of the Jenner Institute at Oxford University, said he hoped challenge tests could begin “by the end of the year”.

Another leading candidate for coronavirus vaccine has also said it is considering challenge tests.

The head of faxing at Janssen, a Belgian pharmaceutical company, said preparations were underway to ensure that coronavirus supplies were available to allow such studies.

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