Drugmakers say 240 million COVID-19 vaccine doses will be ready to ship to US states by the end of March.
An additional 20 million is expected to come from Johnson & Johnson.
The company made the pledge pending FDA approval.
Their single-dose vaccine will go under review Friday.
AstraZeneca is also looking to get U.S. approval for its COVID-19 vaccine by April.
The CDC now says 17% of the U.S. adult population now received at least one-shot.
Meanwhile in Washington, the House is set to vote Friday on President Biden's COVID-relief package.