On Tuesday, President Trump signed an executive order to prioritize Americans for a vaccine ahead of U.S. assistance to other countries.

“It is the policy of the United States to ensure Americans have priority access to free, safe, and effective COVID-19 vaccines,” the order reads.

On Monday, a senior administration official noted that every American will be vaccinated with no cost to them, with no associated deductible, co-pay or insurance.

According to officials working on Operation Warp Speed, as many as 20 million Americans could be vaccinated by the end of the year. That includes more than six million doses of the Pfizer vaccine ready to ship as soon as the FDA authorizes it, which could be as soon as this weekend.

The CDC has recommended the first doses go to health care workers and residents of long-term care facilities, though the decision is ultimately up to states. 

Officials expect another 30 million people to be vaccinated in January, with numbers increasing each month until there are enough doses to vaccinate all Americans by the summer.

Once U.S. officials have determined that there are enough doses of vaccines for all Americans, the president’s executive order then directs the Department of Health and Human Services, the State Department, the U.S. Agency for International Development (USAID) and others to “facilitate” international access for U.S. allies, partners and others.

Speaking about the executive order Monday, a senior administration official said that helping other countries get access to vaccines would be “in the interest of the United States.”

The president’s executive order came as part of a White House vaccine summit Tuesday afternoon, which included the country’s top health officials, representatives from FedEx and UPS, who will deliver vaccines, spokespeople for CVS and Walgreens and the Republican governors of Florida, Louisiana, Texas and Tennessee.