A person is considered fully vaccinated 2 weeks after administration of the final dose in the primary vaccination series (that is, at least two weeks after a single dose of the Johnson & Johnson vaccine [unless two doses are recommended in the country] or at least two weeks after receiving a second dose with any other vaccine approved for WHO Emergency Use Listing).
A person is considered “boosted” and up to date after getting their booster dose.
Current national recommendations may differ depending on a person’s age, health status, and date of the first vaccination. Many people who are immunocompromised may need an additional dose as part of their primary vaccine series.
As with vaccines for other diseases, people who are up to date are optimally protected.