This chart shows the primary vaccine coverage ratio across UN subregions. It is calculated as the number of primary doses administered divided by the total population. Full coverage is achieved at 200 primary doses per 100 people.
Note that primary doses are the doses administered as per the primary (first) vaccination cycle, exclusive of boosters. We distinguish from boosters to be able to compare vaccination progress across countries and country groups during the first round of vaccinations.
There is one more twist. The vaccine coverage ratio for primary doses represents a new way of assessing global vaccination progress that yields consistent comparisons across countries that are invariant to the mix of vaccines used. The method employed is to convert all primary doses administered into double-dose equivalents. That means that doses belonging to 1-dose protocols are multiplied by 2 whereas doses belonging to 3-dose protocols are multiplied by 2/3. With this adjustment, we achieve 200 as the full coverage milestone for primary vaccinations.
For further details on the adjustment method, check out this post and the background note below on double-dose equivalents and other aspects such as the country classification and the universe of countries.