President Joe Biden holds his face mask as he speaks on COVID-19 on Tuesday in the State Dining Room of the White House in Washington. Credit: Evan Vucci / AP

WASHINGTON — White House coronavirus response coordinator Jeff Zients said it’s essential that Congress pass President Joe Biden’s COVID-19 relief bill to keep the momentum on vaccinations and more testing capacity to contain the virus.

Zients said The administration is committed to delivering on Biden’s goal of 100 million shots in 100 days, and more if doable, Zients said. But his top aide, Andy Slavitt, also said 500 million shots would be needed to vaccinate all Americans 16 and older.

Biden’s “American Rescue Plan” has a total price tag of $1.9 trillion, which is making some Republicans in Congress balk. But most of the cost is to shore up the economy.

About $400 billion is for measures specifically aimed at controlling the virus, including dramatically increasing the pace of vaccinations and building out an infrastructure for widespread testing.