Saad Omer, Yale researcher and WHO official: "The end game of this pandemic is a safe and efficacious vaccine that a high number of people take."... They measured which appeals — like self-interest, community interest, guilt or embarrassment — would result in "intended vaccine uptake" and found the most successful messages were those that viewed "vaccination as a collective-action problem."... Omer: "Speaking to people's values has the potential of moving people in terms of their taking an action."