Controversial ‘Human Challenge’ Trials for COVID-19 Vaccines Gain Support

July 21, 2020

(Science) – Since the early days of the pandemic, some researchers have advocated a fast way to determine whether a COVID-19 vaccine works: Intentionally attempt to infect vaccinated volunteers with the virus, SARS-CoV-2. Ethicists and vaccine scientists alike raised red flags, and the discussion has remained mostly theoretical. But now two key elements are taking shape: a large corps of volunteers willing to take part in a “human challenge” trial, and the well-understood lab-grown virus strains needed for the studies.