Oh, BS! The parts of the world that will take longest to receive vaccinations are also parts of the world to which infected people are unlikely to travel. Ignoring that, the several major vaccine mfrs have each set a goal of manufacturing 1 billion doses a year in their first year of production. So, just considering Pfizer, Moderna, J & J, and Novavax (i.e. ignoring 100-200 other vaccines!), they will have manufactured enough for every person in the world by the end of 2023 or so.