VANCOUVER — Would you voluntarily get infected with COVID-19 to help test a new vaccine?
Preparations are underway in some parts of the world for what are known as human challenge trials.
Although no such studies are currently approved, there are people in B.C. and across the country who are ready and willing to take part in the hopes of bringing an end to the pandemic.
The search for a COVID-19 vaccine has been a global race ever since the pandemic began earlier this year. As of now, there are 180 COVID-19 vaccine candidates worldwide.
But while typical large-scale trials to determine a vaccine’s efficacy can require tens of thousands of participants, human challenge trials can operate with fewer people. Participants are given a new vaccine, and then be deliberately exposed to the virus in a controlled environment.
Twenty-seven-year old Kelowna resident Conor Barnes is willing to volunteer for such a study, and has signed up with the U.S.-based campaign One Day Sooner, which is advocating for such trials.
“In the end I decided that for me, the risks were outweighed by the benefits,” Barnes said, and added he researched the topic first and believes it’s important to think it through thoroughly before making a decision. “If I can take on that risk voluntarily and reduce that risk for thousands of others, how could I say no?”
One Day Sooner communications director Abie Rohrig said researchers in the U.K. and the U.S. are still making preparations, even without a planned trial.
“It’s important to prepare for challenge trials today, if we need to use them tomorrow,” Rohrig said. “That means parliament should fund things like the construction of bio-containment facilities to house volunteers during a challenge study, and should begin preparing a strain of the coronavirus that could be used in a challenge study.”
Rohrig said preparations for potential challenge studies have just begun within the last couple of months, including at Oxford’s Jenner Institute. He added the sheer number of vaccine candidates is a reason to consider challenge trials.
“Human challenge trials, what the World Health Organization (WHO) suggested in May, can help us quickly narrow the field of promising vaccine candidates, so we can know which of these 180 vaccines actually work, and allocate resources accordingly,” Rohrig said.
Over 36,000 people from around the world have signed up with One Day Sooner to express their interest in volunteering in such a trial, and Rohrig said that includes “just about 2,000” people from Canada.
Rohrig added another reason for challenge studies is the ability to answer unique biological questions about COVID-19 that would be “complimentary” to a typical Phase 3 trial, such as reinfection and the early stage development of the illness.
He said there’s also the fact that the world will likely need “many” vaccines to meet global demand, while keeping in mind the manufacturing and supply chain capacity.
“That requires a second generation, even a third generation of vaccine candidates that have different methods of manufacture than the first generation, and improve upon the first in terms of its efficacy,” Rohrig said. “So that’s where challenge trials can come into play.”
As of Sept. 3, Health Canada had not received any applications for challenge trials, nor does the government have specific guidelines for such trials in Canada.
In May, WHO published guidelines for how challenge trials can be ethically acceptable, including limiting initial studies to young healthy adults aged 18 to 30.
“Such studies can be particularly valuable for testing vaccines,” the guideline document said, and noted challenge trials have been performed “safely in tens of thousands of consenting adult volunteers” over the last 50 years.
“These studies have recently helped, for example, to accelerate the development of vaccines against typhoid and cholera, and to determine correlates of immune protection against influenza.”
The document also outlined how challenge studies are “ethically sensitive” and must be carefully designed and carried out.
Clinical professor Stephen Hoption Cann with the University of British Columbia’s School of Population and Public Health said he doesn’t think the evidence is there to necessitate a challenge study for a COVID-19 vaccine at the moment.
“The only way I could see that is if the infection rate declines quite dramatically and you just don’t have enough natural infections occurring, and you’re still trying to develop your vaccine,” he said.
Hoption Cann added safety is a key concern with such studies, as there is no effective treatment for COVID-19.
“This is a new virus that we don’t really know how easy or how difficult it’s going to be,” he said. “Sometimes people have rare, adverse reactions.”
Hoption Cann pointed to the British drugmaker AstraZeneca’s recent vaccine trial being put on hold while it investigates whether a volunteer’s illness is connected.
He also noted a planned human challenge trial involving a potential vaccine for Zika virus was called off due to safety concerns for participants.
“There’s been discussion by the (U.S. Food and Drug Administration), the (U.S. Centers for Disease Control and Prevention), saying there may be a vaccine available by the end of this year, and a lot of people think early next year,” Hoption Cann said. “So you know over time there’s going to be no shortage of vaccines, and I’m sure there are some that are going to turn out effective, we just have to wait it out.”
Barnes said while it’s not clear if he’ll get a chance to participate in such a trial in Canada, he thinks it’s time to be “inventive” when it comes to tackling the virus.
“We can’t get too used to how bad this is,” Barnes said. “The pandemic is bad in so many ways, economically and all the deaths and long term effects. I think we need to think creatively about ways to end it sooner.”
In an email to CTV News, Health Canada said it could be possible to conduct a human challenge trial if carefully controlled. But before that happens, they need enough information about the potential risks of the virus and how they can be mitigated.
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