EditorialDr. Jeffrey Kahn, the director of the Johns Hopkins Berman Institute for Bioethics, opposes the idea of human challenge trials for a coronavirus vaccine. (Rosem Morton/The New York Times)
EditorialDr. Jeffrey Kahn, the director of the Johns Hopkins Berman Institute for Bioethics, opposes the idea of human challenge trials for a coronavirus vaccine. (Rosem Morton/The New York Times)