By ZOE MAGEE, ABC News

(NEW YORK) — In a bid to speed up the race to find a vaccine for the novel coronavirus, the U.K. government announced Tuesday morning that it will be launching some controversial vaccine trials known as challenge trials.

In a world first for COVID-19, young healthy volunteers will be vaccinated, then intentionally exposed to the potentially deadly virus in order to test vaccines in a controlled environment. Although some medical experts view them as ethically questionable, the benefit of challenge trials is that they can be completed in a much shorter timeframe than typical late-stage studies.

The experiment will take place in a quarantine ward of a north London hospital. After inhaling a diluted dose of the virus, the trial participants will be closely monitored, thus enabling scientists and doctors to better understand the disease and how a vaccine can fight it.

“Human challenge studies can increase our understanding of COVID-19 in unique ways and accelerate development of the many potential new COVID-19 treatments and vaccines,” explained Dr. Chris Chiu, from the Department of Infectious Disease at Imperial College London and lead researcher on the human challenge study.

The 1Day Sooner advocacy group, which has been petitioning the government to allow challenge trials, hailed the announcement.

“We are glad the U.K. government is embracing the altruism of the thousands of our British volunteers who want these studies,” the group said.

The advocacy group says these trials “will be key to making multiple safe and effective COVID-19 vaccines available for the whole world, including those in low-income countries bearing the brunt of this pandemic.”

It says it believes these trials will not only accelerate research into vaccines but “will also answer essential questions about COVID-19 immunity that are broadly applicable to the development of treatments and public health policy.”

Alastair Fraser-Urquhart, 18, a spokesperson for 1Day Sooner, explained to ABC News his motivation to volunteer for these trials. Brushing aside the fact that he’s putting himself at risk, he said, “I’m convinced that challenge trials will save thousands of lives and billions of pounds, and if I didn’t do something and I wasn’t advocating challenge trials I would regret it.”

Andrew Catchpole, the chief scientist of hVIVO, the company that will be running the trials in conjunction with the British government, Imperial College University and the Royal Free Hospital, stressed to ABC News that as much risk as possible has been removed from the process.

Only people ages 18 to 30, proven to be healthy, will be taken as volunteers, according to Catchpole, and the dose of the virus that they will be exposed to will be very carefully calibrated.

“So just like any other clinical trial, what you would expect is that any product we put into a human needs to undergo very tight regulations, and this is no exception to that,” Catchpole said.

“So the virus, which we would inoculate them with, has been manufactured to the very high standards, a medical grade version of the virus that undergoes very high regulatory scrutiny to make sure that that virus is safe and suitable for use — just like you would expect for any other licensed medicine,” he added.

The dosage will be low to reduce the risk of volunteers experiencing severe symptoms, but doctors still need to get the balance just right.

“We are looking to induce infection, but not necessarily looking to induce disease,” Catchpole said.

Once the volunteers have been successfully infected, they will be closely monitored in a quarantine ward of the Royal Free Hospital.

“The body, once inoculated with the virus, starts to produce various reactions within itself,” Martin Johnson, Hvivo’s senior medical director explained. “And that’s what we need to measure. We need to understand what the exact response of the virus is right from the word ‘go,’ in a safe environment.”

Everyone involved with the project is keen to stress that safety is paramount and that the World Health Organization’s guidelines will be followed to the letter.

“Our number one priority is the safety of the volunteers. My team has been safely running human challenge studies with other respiratory viruses for over 10 years. No study is completely risk free, but the Human Challenge Programme partners will be working hard to ensure we make the risks as low as we possibly can,” Chiu said.

While there is a precedent for challenge trials, they are typically conducted for diseases for which there is a robust treatment or cure, so that volunteers can be rescued should they fall ill.

“In the U.K., we’ve got a very long history of safely conducting challenge studies,” Johnson said. “And therefore, we have a very, very well-established regulatory framework for doing exactly that and ensuring that the ethics of doing this are really closely scrutinized.”

Tuesday’s announcement shows that as Britain carves out a new identity in the post-Brexit era, it is determined to keep its seat at the top table of medical and scientific advancements; in fact, according to Catchpole, it wants to consolidate its position as a world leader in the field.

“The U.K. government is very keen to establish a challenge trials platform to respond not just to this pandemic, but also future pandemics,” he said.

But as the hVIVO team explained, challenge trials can be an incremental process, and it may take time for doctors and scientists to identify the appropriate dose of the virus needed to infect — but not harm — a volunteer patient. Regulatory and ethical approvals are also still pending, although these are expected to be received by November or December of this year, according to Catchpole. The trials will likely begin by next spring or summer.

And the big question: What does all this mean amid the race to find a vaccine?

Catchpole told ABC News that the doctors and scientists involved insist “challenge studies have a key advantage of the fact that you can determine vaccine efficacy very, very quickly (could be as minimal as two months), and you can determine whether you got vaccine efficacy or not. Compare that to traditional field trials and it takes many, many months.”

“And of course, what happens with the traditional studies is you vaccinate people and they go about living their normal lives and it’s just purely by random luck whether they’re actually exposed to the virus or not. Hence, it can take a very long time to establish efficacy in the field,” Catchpole continued. “And you’re totally dependent on how much virus is going on [around] the community. Challenge studies we’re able to conduct safely and all year round, irrespective of how much virus is going on [around] the community.”

The UK’s deputy chief medical officer, professor Jonathan Van-Tam, detailed two main reasons that his government decided to sponsor these trials: “First, for the many vaccines still in the mid-stages of development, human challenge studies may help pick out the most promising ones to take forward into larger Phase III trials. Second, for vaccines which are in the late stages of development and already proven to be safe and effective through Phase III studies, human challenge studies could help us further understand if the vaccines prevent transmission as well as preventing illness.”

The U.K. government will not yet reveal which vaccines will be tested in these trials, and Johnson warned that they might not even be overwhelmingly successful. He noted that previous attempts at finding vaccines have proved elusive.

“If you take when the Spanish pandemic was around in 1919, almost exactly 100 years later, we still don’t have a perfect vaccine for influenza,” he said, adding that our expectations for a coronavirus vaccine need to be tempered. “No, we’re not going to get a perfect vaccine quickly, but hopefully we can try and establish some baselines of what is good at the moment.”

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