President Joe Biden on Wednesday will launch his effort to fight the COVID-19 pandemic by issuing a mask mandate for federal property and federal contractors and by asking people to wear masks in public for 100 days.

Biden has said since the 2020 campaign that his first priority in office will be combatting the coronavirus, which has already killed more than 400,000 Americans while causing untold economic and psychic harm across the country.

His two most important initiatives will be a coordinated effort to speed the pace of vaccination and an economic relief package that he has said will total nearly $2 trillion. The former will be an ongoing effort over the next few months, while the latter will require an act of Congress which will take weeks at least.

Wednesdays action will consist of steps that Biden can take on his own, using his authority to issue executive orders, and they will cover a variety of items on Bidens agenda.

Three will address COVID-19. Here is what they are, according to a press release from Bidens transition team:

A mask mandate and challenge: Biden doesnt have the power to issue a national mask mandate. However, an executive action will require compliance with CDC guidance on mask wearing and physical distancing in federal buildings, on federal lands and by federal employees and contractors. Biden is also launching a challenge to the public, asking the American people to do their part their patriotic duty and mask up for 100 days.

A return to the World Health Organization: The U.S. will rejoin WHO, reversing Trumps decision to withdraw the country from the agency. WHOs executive board is meeting this week. Dr. Anthony Fauci, the nations top infectious disease expert, will lead a U.S. delegation to the meetings and deliver a speech on Thursday.

A reorganization of the federal COVID response: Biden is creating the position of COVID-19 response coordinator, which former Obama administration official Jeff Zients will be filling. It formalizes a role that Zients has been playing during the transition, as manager of Bidens COVID-19 agenda. The same executive order will restore the Directorate for Global Health Security and Biodefense, a special response unit within the National Security Council dedicated to monitoring health threats from around the globe. The Obama administration created it in 2014. The Trump administration disbanded it four years later.