In these strict control tests, volunteers receive a vaccine and, about a month later, are purposely infected with the disease under controlled conditions. They are then isolated in a quarantine facility and monitored to find out whether they become ill or whether the vaccine immunized them.
Preliminary testing work, which aims to accelerate the process that determines the effectiveness of a Covid-19 vaccine candidate, is being carried out by hVIVO, a unit of the pharmaceutical services group Open Orphan, the company told Reuters.
Procedure divides opinions
Supporters of human challenge tests say the procedure is a good way to shorten the often time-consuming process of proving the effectiveness of experimental vaccines, but which have potential.
Critics say that deliberately infecting a person with a potentially fatal disease for which effective treatment does not yet exist is unethical.
Vaccine developers AstraZeneca, Sanofi, BioNTech, Moderna and Inovio said in September that their respective candidates for the coronavirus vaccine are not involved in the British company’s program.