U.S. President Joe Biden will set a new course for global vaccine allocation this week, hosting a summit on the shortage of shots in poorer countries even as the U.S. moves to give booster doses to millions of fully inoculated Americans.

The U.S. plan for boosters will steer tens of millions of doses into the arms of many U.S. adults starting as soon as Friday. That has angered nations where many people are still struggling to obtain a first shot.

As world leaders gather for the United Nations General Assembly in New York this week, Biden aims to counter their criticism by hosting a virtual summit on Wednesday where he’ll propose a target of fully vaccinating 70% of the world by September 2022.