The U.S. is among the countries projected to miss the WHO's Covid vaccination target for 2022, researchers have said, alongside a host of other nations across Europe, Asia and Africa.
In October, the WHO set a target for countries to vaccinate 70% of their populations by mid-2022.
According to projections made by Our World in Data, last updated on Tuesday, more than 100 countries are not on track to meet that goal.
Our World in Data's projections were compiled using official data, with the current vaccination rate for each country calculated as the average number of people who received their second vaccine dose within the past 14 days. Researchers then assumed these vaccination rates would remain constant through to the WHO target of mid-2022.
"By adding this expected share to the share of the population that have already been fully vaccinated, we project what share of people will be fully vaccinated July 1, 2022," researchers said. "We exclude from our projections countries that have not reported figures for more than 30 days."
They acknowledged that their method did not take variables like potential vaccine shortages, changes in vaccination rollout speeds or new government policies into account.
Some of the countries that were not predicted to vaccinate 70% of their populations by the middle of this year included Estonia, Jamaica and Nigeria.
Fewer than 50 countries have already reached the 70% threshold, including Qatar, Portugal and Japan.
Saudi Arabia, Russia and Hong Kong were among those to have not yet surpassed the 70% threshold but were seen to be on track to reach the WHO's target by mid-2022.