The White House on Tuesday warned states that unordered coronavirus vaccine supply will be made available to other states, Jeff Zients, Biden's COVID-19 response coordinator, told the Washington Post.

Why it matters: The shift in vaccine allocation — which comes after the administration reached its 100 million shots-in-arms milestone — would be the most significant shift in domestic distribution since Biden took office.

Details: The White House will add unordered vaccines into a federal bank, available to states where demand for vaccines outpaces supply, per the Post.

• States can order up to 50% above their usual weekly allocation, which will still be determined by the state's portion of the overall U.S. population.

What they're saying: White House Press secretary Jen Psaki confirmed the plan to reporters at Tuesday's briefing, saying that states can still order a full allocation of doses if they want to.