- Coronavirus vaccine research is advancing at an incredible pace, with some of the first results expected by the end of the year.
- The UK government is actively exploring the idea of starting a challenge trial where volunteers would receive the experimental drug and then the virus.
- The World Health Organization (WHO) already cleared the controversial testing method, but governments and vaccine makers are still reluctant to embark on research that would expose volunteers to a deadly pathogen.
- Tens of thousands of people have signed up for challenge trials nonetheless.
There’s hope that vaccines combined with continued precautions (social distancing, hand washing, and face masks) can defeat the COVID-19 pandemic by the end of 2021. While we have no definitive proof that vaccines are effective and safe, there’s plenty of promising evidence to keep the hope alive. First of all, there are hundreds of coronavirus vaccine candidates in the works. The more shots on goal, the higher the chances that at least one will score. Secondly, the results for the first two phases of clinical trials have shown that about a dozen drugs are effective and safe. Phase 3 will have to prove these experimental drugs can block infection or reduce the virus’s severity.
There’s plenty of reticence regarding COVID-19 vaccines as well. More Americans are wary of vaccines than a few months ago, as vaccines became tools to advance political agendas. The scientific community has attempted to reassure that political factors will not compromise vaccine safety, and the new FDA guidelines make it harder for any vaccine candidate to seek an emergency use authorization, or obtain one, before the November 3rd presidential election. The guidelines say that companies will need to observe volunteers for two months before starting the approval process.
But other countries are looking at a more drastic approach for testing the effectiveness of vaccines. Rather than leave COVID-19 exposure to chance for volunteers, the UK is considering infecting some of them intentionally to see if the drugs work. And thousands of people are ready to be exposed to the virus to save others.
The topic of vaccine challenge trials has come up over the summer quite a few times, and there’s a site called 1 Day Sooner that takes registrations for such projects. But it’s Great Britain that seems to be partial to such a controversial experiment.
COVID-19 would not be the first illness where challenge trials are used to test a vaccine. But COVID-19 has no cure, meaning there’s no alternative for the patients who get infected intentionally. If the vaccine doesn’t work, they’ll have to deal with the ensuing infection, just like regular patients. Cholera, typhoid, malaria, and the common cold are some examples were challenge trials had been used, explains CNN.
The UK is in active conversations on COVID-19 challenge trials, which would be the first in the world. But some of the companies that developed the current coronavirus vaccine frontrunners won’t participate — the list includes AstraZeneca, Sanofi, and BioNTech.
“It’s not clear that necessarily the first vaccines to be evaluated are going to be the best vaccines,” Peter Smith of the London School of Hygiene & Tropical Medicine told CNN. “I think there’s a very strong case for exploring challenge trials to evaluate vaccines for a large number of potential Covid vaccines in development.”
The challenge trial discussions are so advanced that the UK’s Health Research Authority (HRA) already has a panel on standby to evaluate the ethics behind such plans.
“There’s very little research that carries zero risk,” said Terence Stephenson, who heads the HRA. “Every day in this country and every country, health care professionals voluntarily put themselves at risk to care for other people.
“People who, in their judgment, might be willing to do that for the benefit of wider society — I don’t personally find that surprising.”
The WHO already agreed in principle to coronavirus challenge trials months ago, setting up protocols for such programs.
COVID-19 challenge trials have critics as well. One main problem with the tests is that they might be limited to young, healthy people who won’t represent the entire population.
One other problem concerns the control group. Clinical trials divide people into two groups, and the volunteers will not know whether they got the actual drug or a placebo. The control group is needed in regular trials to assess the effectiveness of the drug. CNN explains that some people think challenge trials will not require placebo groups, as everyone is getting a vaccine candidate and then the virus. Others think that human errors might lead to wrong conclusions without a control group. And therefore, some of the volunteers would have to be infected with the virus after getting a placebo vaccine shot.
“The problem,” Smith said, “is essentially that if you give a group of volunteers a vaccine, and then you challenge them, and none of them develop disease, is that because the vaccine was protective, or because there was something wrong with the way in which you challenged them such that they didn’t get infected? And you can’t answer that question definitively unless you have a control group.”
As with regular trials, there’s no guarantee that a challenge trial would deliver the positive results we need from vaccine candidates.
It’s unclear when a challenge trial would start and how long it would take to produce results. But nearly 40,000 people in 166 countries have signed up to volunteer on 1 Day Sooner, and the number will continue to grow.
