Nearly 14,000 volunteers from 102 countries have signed up for a COVID-19 challenge study.
Rabat – The World Health Organization (WHO) has suggested infecting healthy volunteers with COVID-19 may accelerate the pace of finding a vaccine.
“Deliberately infecting healthy volunteers with the virus that causes Covid-19 may speed studies of vaccines against the deadly pathogen,” the organization said.
In response to WHO’s suggestion, a working group of the UN health agency said in a report posted Wednesday on its website that “such studies, which pose significant potential dangers to subjects, may be considered in dire situations and with certain disclosures and protections.”
Such medical research studies are called “human challenge studies” and are sometimes required to study diseases and their treatments.
Challenge studies “can be substantially faster to conduct than vaccine field trials,” added the working group. They further explained that this is “in part because far fewer participants need to be exposed to experimental vaccines in order to provide (preliminary) estimates of efficacy and safety.”
The process of deliberately infecting people can only be carried out under eight conditions specified by the WHO. The conditions include scientific justification, an assessment of potential benefits, and the fully informed consent of all subjects.
The health agency also specified that initial studies should be limited to young, healthy adults aged between 18 and 30 years old, in addition to prioritizing those who are most likely to get infected, with the exclusion of the poor and socially vulnerable.
The report specified that healthcare workers and researchers would be particularly appropriate for coronavirus challenge studies, as they already face a higher probability of infection and are well aware of its risks.
While challenge studies have the potential to reduce the global rate of COVID-19 mortality, scientists led by Marc Lipsitch, a Harvard School of Public Health epidemiologist, implied that the medical research studies pose significant potential dangers for volunteers.
“Obviously, challenging volunteers with this live virus risks inducing severe disease and possibly even death,” the scientists said in an article published March 31 in the Journal of Infectious Diseases.
Scientists would test the vaccines on a large group and compare the results with those of a control group of unvaccinated people.
Moderna’s Inc. chief medical officer, Tal Zaks, does not believe that the method will be effective in finding a vaccine.
Zaks said he is skeptical that a challenge study, which could take months to design and implement, would speed development of the company’s product. The potential vaccine is already entering the second of three phases of study.
“The shot would have to prevent the development of the disease, not just mild infections, or it would be hard to know if the dose picked was the right one,” he said.
The COVID-19 challenge study has seen nearly 14,000 volunteers from 102 countries signing up to date.