U.S. researchers will create a strain of the coronavirus that could be used in possible vaccine tests called human challenge experiments, said Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases, in an interview Friday.
© Julia Robinson / For the Washington Post
Lehua Gray has volunteered to test a vaccine for covid-19 through a website called 1Day Sooner, which aims to reduce the time it takes for FDA vaccination approval by Crowdsourcing volunteers. (Julia Robinson for The Washington Post)
The United States is not engaged in initiating such ethical testing, but has begun the process of creating a strain of coronavirus strain that could be used to infect humans, in case such trials become necessary, Fauci said. . He called it a “Plan C or Plan D”, a preliminary step that is being taken because creating a tribe that meets exact regulatory standards will take months. Large trials of 30,000 individuals testing the effectiveness of experimental faxes are likely to yield results sooner and provide much-needed safety data.
Load error
‘You do that in general [human challenge trials] if you do not have enough infections in the community at some point to get a signal from the vaccine, “Fauci said.” Unfortunately for us, we do not have that problem – we have a lot of infections. ”
Typically, researchers test vaccines by injecting people with the experimental drug as a placebo and waiting to see if those who received the real vaccine develop fewer cases or less severe illness after being exposed to a virus in daily life. . To tell if a coronavirus vaccine is 60 percent effective, Fauci has estimated that 150 to 160 people within the 30,000 who participate in each trial should become ill, for example.
In challenge studies, people would be exposed to the virus after an experimental vaccination. The idea has gained popular support through an organization called 1Day Sooner, which has enrolled more than 30,000 volunteers who take personal risks to speed up the scientific race for a vaccine. Reuters first reported Friday that the United States would begin taking steps to prepare for such trials.
Fauci and others have argued several times that challenge experiments are likely to be slower, more ethically beautiful, and harder to interpret scientifically than many people appreciate. It takes months to create the strains of coronavirus that can be used in such experiments to infect humans. Fauci said a viral strain would not be ready by the end of the year.
Challenge studies are routinely used against diseases such as malaria, which have rescue medications to prevent or moderate disease. There are no similar treatments for covid-19, the disease caused by the coronavirus. There are also concerns that the potential risks of a trial for coronavirus challenge are not yet fully known, as doctors are still learning about the long-term effects of infection. Scientists and companies have said that such trials should not be taken seriously until better therapies exist.
Because challenge studies would likely select from people who are not likely to develop a serious illness and die from the disease, it can also be difficult to extrapolate results to understand whether the vaccine would really protect people at risk for the virus. .
William Phillips, 71, a Nobel laureate in physics, said he had applied to be considered for challenge trials, although he knows there is almost no chance he would be selected because of his age.
‘As a scientist, what I want is data. And it just struck me that challenge trials are a way to get more reliable data faster and faster than a standard trial, ”said Phillips. “From a dispassionate point of view, if you ask yourself: What is the risk-benefit ratio of doing such a thing? Sure, you can kill a few people, to put it kind of blunt, but think about how many people you save if you get a vaccine in circulation sooner. ‘
Even if a challenge test were followed, it would not replace other tears. The safety data collected from the large trials will be essential. But important scientific questions could be answered by human challenge studies if the ethical, scientific, and logistical concerns could be satisfied.
Fauci pointed out that scientists could ask straightforward questions, learning whether a vaccine fully protects people from infection in their upper nasal passages, for example. Such studies can also help scientists understand how many viral particles are needed for someone to become ill.
“We are in the process of getting the system up and running to develop a challenging action [of coronavirus], although we really do not consider it something that we really need to operationalize, “Fauci said.
Continue reading
