In other words, this new guidance specifically focuses on the topic of how to transparently incorporate information across other trials and incorporate benefit-risk into the definition of success. If the FDA reserves the right to move the goalposts somewhat, that is a valid concern! But why not use the principles from its own Bayesian guidance to reach this decision: based on all available data, how likely is it that the vaccine is not as effective in the elderly as its high-dose competitors? What sort of prior assumptions are required to reach this conclusion? The Bayesian principles in this guidance make this project feasible.