SEANA SMITH: As Pfizer's vaccine starts to get distributed this week, and also as we prepare for Moderna potentially being next in line, we want to talk about-- or take a look, I should say, at the role that a US defense agency played in preparing the US to produce a vaccine very quickly. And for that, we want to bring in Regina Dugan. She's the former head of DARPA. And we also have our very own reporter Anjalee Khemlani joining the conversation.

The activities of users of Twitter and other social media services were recorded and analysed as part of a major project funded by the US military, in a program that covers ground similar to Facebook’s controversial experiment into how to control emotions by manipulating news feeds.