GlaxoSmithKline PLC executive Thomas Breuer said on Tuesday he has "reservations" against human challenge trials as a tool for determining the effectiveness of COVID-19 vaccine candidates without a therapy for the infection. The British government said last week it was working with partners on the potential for "human challenge" trials, in which volunteers are deliberately infected after receiving an experimental inoculation. "Yes, younger people are far less likely to observe a severe disease, but it's a little bit of a lottery...so I have reservations in the current context," Breuer, the British group's chief medical officer for vaccines, said at the World Vaccines Congress Washington. Source
