Any COVID-19 vaccine that becomes available in 2020 likely will be administered in a stepwise manner and be used more like a therapeutic to lower the risk in certain populations, rather than to develop herd immunity and end the pandemic, former FDA chief Scott Gottlieb told a group of public health experts and fellow former FDA chiefs last week. Gottlieb’s comments come as the administration deliberates how to allocate the initial doses of a vaccine once it is available, and...