U.S. government scientists have begun efforts to manufacture a strain of the novel coronavirus that could be used in human challenge trials of vaccines, a controversial type of study in which healthy volunteers would be vaccinated and then intentionally infected with the virus, Reuters has learned.
The work is preliminary and such trials would not replace large-scale, Phase 3 trials such as those now under way in the United States testing experimental COVID-19 vaccines from Moderna Inc and Pfizer Inc.
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 in multiple locations, adding months of preparations to coordinate the studies.
Such trials are typically done when a virus is not widely circulating, which is not the case with COVID-19. Many scientists consider human challenge trials of the novel coronavirus unethical because there are no “rescue therapies” for those who fall ill.
Earlier this week, Johan Van Hoof, global vaccines chief for J&J, said in an interview with Reuters that the preparations for such trials are under way across the world, and the company is following those preparations.
Van Hoof said such trials would offer a testing option in case the virus stops circulating widely, but the company would only move forward with such trials if the ethical issues are resolved and an effective treatment is available.