CHICAGO (Reuters) – U.S. government scientists have begun efforts to create a strain of the new coronavirus that could be used in human challenge tests of vaccines, a controversial type of study in which healthy volunteers would vaccinate and then deliberately infect with the virus, Reuters has learned.
FILE PHOTO: A small bottle marked with a “vaccine” sticker is held at a medical syringe for display of “Coronavirus COVID-19” words in this illustration April 10, 2020. REUTERS / Dado Ruvic // File Photo
The work is preliminary and such trials would not replace on a large scale, Phase 3 studies such as those currently in the United States testing experimental COVID-19 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 1 Day Sooner and others who see challenge trials as a way to speed up tests of a COVID-19 vaccine. Most vaccine studies rely on inadvertent infection, which can take time to prevent.
Some drugmakers, including AstraZeneca (AZN.L) and Johnson & Johnson (JNJ.N), said they would consider human challenge testing to test COVID-19 vaccines as needed.
“Should there be a need for human challenge studies to fully assess candidate vaccines as therapeutic effects for SARS-CoV-2, NIAID has begun research into the technical and ethical considerations of conducting human challenge studies,” said the agency’s statement.
This includes efforts to produce an appropriate SARS-CoV-2 strain, establish a clinical protocol, and identify resources needed to conduct such studies.
Small challenge studies would be done in small isolation units to control the virus. Larger challenge studies involving 100 people or so would have to be done at multiple locations, adding months of preparation to coordinate the studies.
Such tests are typically performed when a virus is not circulating widely, which is not the case with COVID-19. Many scientists consider trials of human challenge of the novel coronavirus unethical because there are no “rescue therapies” for those who become ill.
Earlier this week, Johan Van Hoof, global vacciner for J&J, said in an interview with Reuters that the preparations for such trials are all over the world, and the company is following those preparations.
Van Hoof said such trials offer a test option in case the virus stops circulating, but the company would only proceed with such trials if the ethical issues are resolved and effective treatment is available.
Dr. Anna Durbin, a fax researcher at the Johns Hopkins Bloomberg School of Public Health, who has conducted a dozen challenge studies, estimates that it can take nine to 12 months to set up a human challenge test, and another six months. to coordinate tests across multiple test sites.
NIAID said it is continuing to prioritize field studies to evaluate SARS-CoV-2 vaccine candidates, but it opened up the possibility of challenging tears for future generations of vaccines or treatments.
Dr Dan Barouch, a vaccine researcher at Harvard’s Beth Israel Deaconess Medical Center in Boston, who helped design and conduct animal studies on J & J’s COVID-19 vaccine, said he was unaware of manufacturers planning human challenge studies. .
“In the setting of a raging pandemic, you do not have to. You just do a trial and get a real result, ‘he said.
In addition, vaccine tests should be done in healthy young people, said Dr. Kathleen Neuzil, University of Maryland School of Medicine, co-leader of the Coronavirus Vaccine Prevention Network, which was formed by NIAID and tests COVID-19 vaccines.
“A 20-year-old in a challenge study will not actually give us the answer to this vaccine that an elderly person, one with chronic kidney disease, ends up in the hospital,” she said.
Report by Julie Steenhuysen; Additional report by Francesco Guarascio in Brussels; edited by Peter Henderson and Leslie Adler
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