Experiments on humans
Scientists want to infect volunteers to test vaccines
This will speed up their development and answer important questions about COVID-19
Denis Gritsenko, Izvestia
An international group of scientists has proposed specifically infecting COVID-19 volunteers to speed up the development of a coronavirus vaccine. According to the current research protocol, specialists are waiting for the vaccinated to become infected by accident. Some of them encounter infection, others do not. Therefore, it can be difficult to determine the effectiveness of the vaccine. In order to intentionally infect people after vaccination, doctors need to circumvent the ethical code developed by the doctors themselves. Previously, similar studies have already been conducted to combat other infectious diseases, but now this practice has been canceled. Nevertheless, 40 thousand volunteers were found on the Internet who agree to get infected on purpose.
99% safe%
The permissibility of testing vaccines against coronavirus infection with intentional infection of volunteers around the world remains a subject of public debate. According to the current rules, doctors are forced to wait until the required number of observed vaccinated people become infected with COVID-19 naturally in order to test the effect of the drug.
An international group of scientists advocating the lifting of the ban on experiments with infection has developed a mathematical model with which it is possible to calculate the degree of risk of participating in a coronavirus vaccine trial. The peculiarity is that the volunteers will be specially infected with coronavirus. Currently, such a method of testing drugs from COVID-19 is not used anywhere in the world for ethical reasons.
"To help refute existing objections regarding studies with intentional coronavirus infection, we have created a model that will help assess the risks for participants in hypothetical trials," the researchers said in an article describing their calculations (Manheim et al., Exploring Risks of Human Challenge Trials for COVID–19).
According to them, the probability that the tests will be without fatal outcomes among volunteers is 99.85%. The chance that hospitalization will not be required is 98.7%, scientists calculated.
There is a website on the Internet where registration of those wishing to take part in such tests is open. About 40 thousand volunteers from 166 countries have already registered there.
Weighty arguments
The advantage of this kind of testing is the relative simplicity of their conduct. The required number of participants in them is an order of magnitude lower than in the studies that are being conducted now. Allowing the infection of volunteers will significantly increase the speed of vaccine development, scientists suggest.
Also, thanks to this method, doctors will probably be able to answer questions about how COVID-19 develops. For example, to find out how much of the virus must enter the body in order for infection to occur. This question still remains open, since it is impossible to find an answer to it without intentional infection.
Another argument in favor of lifting the ban is the opportunity to pick up participants with good health, the risks of severe illness for which will be minimal. At the same time, for the entire period of testing, volunteers will be under the continuous supervision of doctors, which will further reduce the likelihood of any complications.
In May 2020, the World Health Organization released a document stating that tests with intentional infection of volunteers will be useful in combating the pandemic. At the same time, the WHO is aware that the resolution of such experiments will raise many ethical questions. The organization has compiled a list of universal criteria that any study with intentional infection must meet. They require that the work be carried out according to the highest medical and public standards, and the potential benefits of the study far outweighed the risks.
Pros and cons
Russian experts interviewed by Izvestia expressed different points of view on the possibility of intentional infection of volunteers with coronavirus. Such a test of the vaccine can become, in fact, the baptism of fire of the drug, says Albert Rizvanov, director of the scientific and Clinical Center for Precision and regenerative Medicine of Kazan Federal University (the university is a participant in the project to increase the competitiveness of education "5-100").
– We will be able to observe the real conditions that patients who have been vaccinated will face. Taking into account the fact that vaccines undergo serious safety and efficacy tests on animals, the risks for participants in such studies are minimal," the expert said.
Research with intentional infection is also considered possible by the head of the Laboratory of Biotechnology and Virology of the Faculty of Natural Sciences of Novosibirsk State University Sergey Netesov.
– For healthy young people, this virus is not dangerous. And the vaccine is very necessary for elderly, chronically ill people, and they need it much more than young people. The method described above allows these tests to be carried out quickly and with maximum statistical reliability," said Sergey Netesov.
Such experiments are necessary and permissible provided that ethical standards established by society and enshrined in the form of law are observed, Pavel Demenchuk, Director of the Department of Philosophy and Religious Studies at the FEFU School of Arts and Humanities, is convinced. The first international document regulating the ethical principles of experiments on people can be called the Nuremberg Code (1947), which fixed a set of rules to prevent the horrors revealed during the Nuremberg trial in the case of doctors, the expert recalled.
Intentional infection of volunteers with coronavirus is ethically unacceptable, says the priest, rector of the Church of St. Alexy in Rogozhskaya Sloboda, head of the Center for Research in the Field of Bioethics and High Technologies, MD Candidate of Biological Sciences Vladimir Dukhovich.
– If researchers are sure that a person has formed full protection from the effects of the virus, then why investigate anything at all? – the expert wonders.
But since studies are being conducted, it is clear that there is no such certainty, he pointed out. This means that there is a possibility that during the study, a person will either die in the worst case scenario, or cause harm to his health, the expert believes. The researchers have no moral right to do this, the priest indicated his position.
There has been a practice of controlled infection in the world for quite a long time, said Andrey Vasin, Acting director of the Institute of Biomedical Systems and Biotechnologies of Peter the Great St. Petersburg Polytechnic University. But it concerns only well-studied infections.
– If we talk about SARS-CoV-2, then this is a new virus, still poorly understood. We have a poor understanding of the mechanisms of its pathogenesis, the mechanisms of complications, we have practically no proven effective treatment mechanisms, especially in severe cases," the expert explained.
In his opinion, it is now premature to seriously consider conducting such studies for the coronavirus.
New research methods could save us from the need to conduct most of the clinical trials on humans, says Pavel Volchkov, head of the Laboratory of Genomic Engineering at MIPT.
– Modern technologies are aimed at creating chimeric humanized animal models, where the data we receive from preclinical studies are as close as possible to what a human will have, – the expert said.
Ideally, the maximum approximation of such calculations should be 90-95%. These models will give the same answers as studies on the human population. But no experiments with direct infection of people are impossible, it is inhumane to even discuss them, Pavel Volchkov concluded.
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