States with higher vaccine demand will be able to request more from federal government

President Biden receives a second dose of the vaccine
President-elect Joe Biden receives the second dose of the Pfizer/BioNTech COVID-19 vaccination from Chief Nurse Executive Ric Cuming at ChristianaCare Christiana Hospital on Jan. 11 in Newark, Delaware. Under a new policy announced Tuesday, any vaccine doses that a state doesn’t request from its weekly, population-based allotment will be held in a general pool, and states with higher demand can request additional shots from that surplus. (Alex Wong/Getty Images)