CHICAGO (Reuters) – U.S. government scientists have begun efforts to produce a new type of coronavirus that can be used in human challenge vaccine trials, a controversial study in which healthy volunteers would be vaccinated and then vaccinated. to be intentionally infected with the virus, Reuters has learned.
PHOTO PHOTO: A small bottle labeled with the “Vaccine” sticker is held next to a medical syringe in front of the words “Coronavirus COVID-19” displayed in this illustration taken on April 10, 2020. REUTERS / Dado Ruvic // Photography Photography
The work is preliminary and such tests will not replace large-scale, phase 3 trials, such as those underway in the United States testing COVID-19 experimental vaccines from Moderna Inc (MRNA.O) and Pfizer Inc (PFE.N), according to a statement sent to Reuters by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.
U.S. officials organizing the fight against the pandemic have been under pressure from advocacy groups such as Day 1 Soon and others who see challenging trials as a way to speed up tests of a COVID-19 vaccine. Most evidence for vaccines relies on unintended infection, which can take time to occur.
Some drug manufacturers, including AstraZeneca (AZN.L) and Johnson & Johnson (JNJ.N), have said they will consider human challenge trials to test COVID-19 vaccines if necessary.
“If human challenge studies are needed to fully evaluate candidate or therapeutic vaccines for SARS-CoV-2, NIAID has begun investigations into the technical and ethical considerations of conducting human challenge studies,” the agency said in a statement.
This includes efforts to produce an appropriate type of SARS-CoV-2, to design a clinical protocol, and to identify the resources that will be required to conduct such studies.
Small challenging studies would be done in small isolation units to control the virus. Larger challenge studies involving 100 people or more would have to be done in different locations, adding months of preparation to coordinate studies.
Such tests are usually done when a virus is not circulating widely, which is not the case with COVID-19. Many scientists consider the trials of the human challenges of the coronavirus novel unethical because there is no “rescue therapy” for those who get sick.
Earlier this week, Johan Van Hoof, head of global vaccines for J&J, told Reuters in an interview that preparations for such trials were being made around the world, and the company was following those preparations.
Van Hoof said such trials will provide a testing opportunity in case the virus stops circulating widely, but the company will only move forward with such trials if ethical issues are resolved and an effective treatment is available.
Dr Anna Durbin, a vaccine researcher at Johns Hopkins Bloomberg School of Public Health who has conducted a dozen challenge studies, estimates that it may take nine to 12 months to establish a trial of human challenges, and another six months. to coordinate testing across multiple test sites.
The NIAID said it was continuing to prioritize field trials to evaluate candidates for SARS-CoV-2 vaccines, but it opened up the possibility of challenging judgments about future generations of vaccines or treatments.
Dr Dan Barouch, a vaccine researcher at Harvard Beth Israel Deaconess Medical Center in Boston who helped design and conduct animal studies on J&J COVID-19 vaccine, said he was not aware of any manufacturers planning human challenge studies.
“In setting up a retreating pandemic, you do not need it. You just make a judgment and get a real result,” he said.
Furthermore, vaccine trials should be made in healthy young people, said Dr. Kathleen Neuzil, University of Maryland School of Medicine, co-director of the Coronavirus Vaccine Prevention Network, which was formed by NIAID and is testing COVID-19 vaccines.
“A 20-year-old in a challenge study will not really give us the answer of the willingness for this vaccine to be kept by an elderly person, someone with chronic kidney disease, to end up in hospital,” she said.
Reporting by Julie Steenhuysen; Additional reporting by Francesco Guarascio in Brussels; editing by Peter Henderson and Leslie Adler