Despite recent advances in treating Covid, experts disagree on whether the challenge trials are justifiable.
Alex Greer says he would rather get directly in the path of coronavirus than be surprised by the illness after a night out at the pub or with friends. It is a scenario that could soon become reality.
Britain is moving closer to conducting studies that would intentionally infect healthy people with the virus to aid researchers in their search for Covid-19 vaccines, and thousands of volunteers like Greer, a chemistry student at Durham University in the Northeast England, they’re ready to go. . Open Orphan Plc, parent of human challenge trials specialist hVivo, has said it is in talks with potential clients, including the UK, to test Covid injections.
Such studies can help accelerate vaccine development and provide scientists with new insights into a disease that has spread to more than 37 million people worldwide, but would expose participants to a threat for which there is no cure. . Numerous questions about the virus, which the volunteers would likely have sprayed on their noses, remain unanswered. Even young people can face dangers.
“I can’t lie and say it doesn’t cross my mind,” said Greer, 20. “The long-term consequences of Covid have yet to be fully investigated and that needs to be taken into account. But I think the potential test successes outweigh that small risk for me.”
Despite recent advances in treating Covid-19, experts disagree on whether the challenge trials are justifiable. One uncertainty is why some young and otherwise healthy people end up with complications months after experiencing mild symptoms, according to Seema Shah, a bioethicist at Chicago’s Lurie Children’s Hospital and Northwestern University.
Crossing a line
“This would really cross a line that people have drawn in terms of when it is ethically acceptable to do challenge studies,” he said. “In the past, it was about diseases that we know a lot more about. We are still learning a lot about Covid-19.”
Companies like AstraZeneca Plc, an Oxford University partner on an experimental coronavirus vaccine, suggested earlier this year that declining infection rates could make it difficult to conduct conventional tests that wait for people to contract the virus from naturally in the community at large. However, Covid continues to spread, allowing several projects to move to the final stage of clinical trials.
Favorites Pfizer Inc. and AstraZeneca say they have no plans to do challenge studies. Other vaccine manufacturers like Johnson & Johnson are watching them warily. The US National Institute of Allergy and Infectious Diseases, a partner of biotech company Moderna Inc., has begun manufacturing a strain of the virus that could be used for challenge studies and is investigating technical and ethical considerations.
“We will only go in this direction if the ethical, medical and safety parameters are clear,” said Thomas Lingelbach, CEO of Valneva SE, a French company working on another experimental Covid injection.
Efficacy comparison
The idea is gathering momentum. 1DaySooner, a group that advocates for people who want to join challenge studies, says it has attracted more than 38,000 volunteers. The UK studies would likely be the first such tests in the world for Covid-19.
“I’m sure it will happen,” said Robin Shattock, an infectious disease expert at Imperial College London. “The difficulty is knowing what it will actually accomplish and if it will do something faster.”
Various forms of human challenge studies have been used for centuries, but good practices and guidelines for ethics and safety were adopted only about 50 years ago. The approach was key to the development of vaccines for diseases such as cholera, malaria and typhoid fever.
No deaths have been recorded in provocation trials in recent decades, research shows, and studies have been safely conducted in tens of thousands of consenting volunteers. However, unlike Covid-19, many of the diseases these trials targeted had well-established treatments.
Challenge studies could play an important role as scientists seek to take advantage of the first generation of Covid inoculations, according to Northwestern’s Shah. They can offer a way to compare efficacy, allowing the best prospects to advance into larger studies and address issues such as the persistence of vaccine-induced immunity.
National Support
UK support, along with therapies like Gilead Sciences Inc.’s remdesivir for patients who become ill, would boost the campaign. Eli Lilly & Co. and Regeneron Pharmaceuticals Inc. last week asked US regulators for emergency use authorizations for their antibody treatments, and many other companies are moving forward with potential weapons as well.
“If the UK can participate in human provocation trials, we will be leaders in this area of science,” said Jennifer Wright, a 29-year-old volunteer who is pursuing her PhD in physics at the University of Glasgow. “It should be the countries with the most money that lead this type of effort, because we are the ones who presumably will not suffer so much.”
The problem is intensifying as the virus progresses and governments are looking for a way out of the worsening economic damage to travel, tourism, retail and many other industries. Risks would be minimized as much as possible by selecting younger people who have no underlying health conditions and keeping volunteers under constant observation, according to the proponents.
“There is pretty clear evidence around the world that young people are the least susceptible to serious disease,” said Adrian Hill, director of the Jenner Institute in Oxford. “Everyone would agree that it would be nice to have something other than remdesivir, but it’s not even clear if you would need to remdesivir.”
Such studies in the US would not replace large end-stage trials, according to the NIAID. Data from ongoing conventional trials will be available by the end of 2020 and will be used to evaluate future challenge studies “if necessary and deemed safe and ethical to employ,” the agency said in an email.
Any UK plan would still have to overcome hurdles, including approval from regulators and an independent ethics committee.
“Given the state we are in with respect to the epidemic and the urgent need for multiple effective vaccines, I think there is a very compelling case left to go on,” said Peter Smith, epidemiologist at the London School of Hygiene and Tropical Medicine.
The main question is whether the studies clearly “would make a big difference,” Northwestern’s Shah said. “I just don’t know yet if there is a solid reason to keep going.”
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