Of course, here in the UK we're high up in the race to get our population vaccinated, or that's what it looks like. Still, we're an experiment (lab rats?) with the rest of the world watching.
Will it work or won't it? Will the 'vaccinated' - half-vaccinated with a single dose, feel 'safe', believe the problem's solved and abandon social distancing, masks and hand washing? Will they mix with friends and family? Will they catch Covid? What are the outcomes for the 'first dose only' victims?
A report from Israel -where they follow Pfizer/BioNtech protocol in giving the second dose of the coronavirus vaccine three weeks after the first: