... start allocating unordered vaccines to other states.

The Washington Post described the change in policy as "the most significant shift in domestic vaccine distribution" since Biden took office, and "part of an effort to account" for flagging demand in parts of the country.

According to the new plan, each state's share of the total US adult population will still determine weekly allocations.

But instead of allowing unordered doses to carry over week-to-week, the White House will instead steer untapped vaccines into a federal bank available to states where demand continues to outstrip supply. Those states will be able to order up to 50% above their weekly allocation.

The "use it or lose it" strategy could put more pressure on states to make sure their citizens accept the vaccines, even prompting them to try different strategies, like abandoning mass vaccination sites in favor of sending jabs to small private practices where patients can receive the vaccine from their regular doctor. Doctors have been mulling these alternative distribution strategies, warning that it could increase the costs associated with mass vaccination. However, in order to reach the 70% threshold for artificial herd immunity, there might not be another option.