Allow healthy volunteers to be infected with coronavirus to speed up vaccine trials, US lawmakers tell FDA
As Americans continue to grapple with the COVID-19 pandemic, US lawmakers have suggested that healthy volunteers should be allowed to be infected with SARS-CoV-2 (the virus that causes the disease) to speed up vaccine trials.
The controversial and radical proposal is referred to as a human challenge, which aims to speed up the testing of a vaccine by months, offering quick evidence if a shot works or does not.
Under current processes, the approval timeline for vaccines ranges from 18 months to several years. A letter, led by Congressman Bill Foster and Congresswoman Donna Shalala, argues that owing to the enormous human costs of the COVID-19 pandemic, a more rapid process is necessary.
Specifically, it requests the US Food and Drug Administration (FDA) to consider testing vaccines using "challenge trials" that many experts believe can reduce the time required to test a COVID-19 vaccine to 2-3 months while minimizing the health risk to test subjects.
"We are writing to ask you to begin consideration of the conditions under which a COVID-19 vaccine might be approved and deployed more rapidly than under the usual approval process. This consideration must rest on a rational analysis of the risk/benefit ratio, based on the best available science, and be free of political interference," states the letter addressed to Alex M Azar, secretary of the US Department of Health and Human Services (HHS), and FDA Commissioner Stephen Hahn.
It has been signed by 35 members of Congress.
“Every week of delay in the deployment of a vaccine to the seven billion humans on Earth will cost thousands of lives. Human misery also results from the economic damage caused by COVID-19 pandemic, and by the tragic psychological impact of social isolation on humans of all ages."
"Therefore, in addition to proceeding along the normal route for developing an approved vaccine for COVID-19, we urge you to consider adopting, in parallel, expedited procedures for testing, approval, and use of COVID-19 vaccines," they write.
The letter emphasizes that rapid vaccine development balances risks to human health of voluntary test subjects in clinical trials, the risks of early deployment of a moderately tested vaccine to the general population, and the certainty of human suffering and death from delayed vaccine deployment.
"We write to assure you that Congress understands that a more risk-tolerant development process is likely appropriate in the case of a COVID-19 vaccine."
"In the case of accelerated human trials, justifiable risks may be taken by parallel testing of multiple-dose levels, advancing more rapidly from phase to phase and potentially by challenge trials that involve deliberately infecting volunteers who have received candidate vaccines or placebos to confirm the efficacy of those vaccines and are at very low risk of serious disease from the infection."
"This could accelerate the emergency use and eventual licensure of vaccines that have also shown safety in larger groups by many months,” says the letter.
It adds, "We urge you to consider these and other options, provided they proceed with the principle of informed consent of truly voluntary subjects and are backed by the best available science."
"Our situation in this pandemic is analogous to war, in which there is a long tradition of volunteers risking their health and lives on dangerous missions for which they understand the risks and are willing to do so to help save the lives of others," the letter says.
As of April 22, over 825,300 cases have been reported from across the US and 45,070 have died in the COVID-19 pandemic, according to the Johns Hopkins tracker. According to the World Health Organization (WHO), five candidate vaccines are currently in clinical evaluation and 71 candidate vaccines are in preclinical evaluation.
Human challenge started by US, UK team
Scientists have already launched a human challenge that asks healthy volunteers to get infected with the new coronavirus. The research team includes Nir Eyal from the Center for Population-Level Bioethics and Department of Philosophy, Rutgers University, US and Department of Health Behavior, Society and Policy, Rutgers School of Public Health, US; Marc Lipsitch from the Department of Epidemiology, and Departments of Immunology and Infectious Diseases at Harvard TH Chan School of Public Health, US; and Peter G Smith from the Tropical Epidemiology Group, London School of Hygiene & Tropical Medicine, UK.
"Human challenge trials deliberately expose volunteers to infection, in order to study diseases and test vaccines or treatments. They have been used for influenza, malaria, typhoid, dengue fever, and cholera."
"Researchers are exploring whether human challenge trials could speed up the development of a vaccine for COVID-19, saving thousands or even millions of lives," reads the information on the website — COVID-19 Human Challenge Trial.
The website answers several questions describing the proposed trial, its potential impact, how it can help speed up vaccine development, the risks to volunteers, and how such risks will be minimized.
People can go on the website and sign up for the initiative. As of April 22, over 1400 volunteers have signed up from across 44 countries, according to details on the website.
In a separate report, an expert writes that in the case of COVID-19, a challenge study could take advantage of the lower rate of death in 18-29-year-olds. "In that age group in China, the death rate was 0.03%, not negligible but relatively uncommon.
"Nevertheless, a challenge study would require controls who receive no vaccine and who might become ill," says Stanley A Plotkin, pediatrics, University of Pennsylvania, US, and Arthur Caplan Bioethics, New York University, US.
"Of course, such studies put volunteers at risk of disease and death and deaths have occurred in drug studies. The ethics of such trials, as well as their acceptability to regulators as a step towards emergency use of a candidate vaccine, are foremost and require immediate discussion," experts write.