From article: In the US, this would mean vaccinating between 197 million and 230 million citizens. Globally, it’d be between 4.7 billion and 5.5 billion people.
Though that depends on the equitable distribution of the vaccination
What is equitable distribution? Should those who got the placebo during testing be first? Should the elderly or the essential worker come first? How should we account for counties' success / failure, and their current situation in distributing vaccines? Should we account for a country's likeliness for internal equitability? What about their capability for distribution, given the mRNA require expensive cooling systems?