The U.S. is working to vaccinate a high percentage of its population against COVID-19 as soon as possible to stop the spread of the disease and end the outbreak in the country.
The mission becomes even more urgent as coronavirus variants emerge around the world, raising concerns that the virus could evade our efforts to control it, if the spread is not curbed quickly.
Since vaccine distribution began in the U.S. on Dec. 14, more than 24 million doses have been administered, reaching 6.2% of the total U.S. population, according to federal data collected by the Centers for Disease Control and Prevention. The U.S. is currently administering around 1 million shots a day.
Strategies for distribution — along with the efficiency and equity of the process — vary from state to state. Alaska and West Virginia lead the vaccination charge on a per capita basis; Alaska has reached more than 11% of their residents with initial shots and West Virginia nearly 10%.
In addition to the states, the federal government distributes vaccines to four federal agencies, five U.S. territories and three freely associated states.
Currently, the two COVID-19 vaccines that have been authorized for emergency use each require a two-shot regimen spaced out by three or four weeks. Vaccination is not complete until both doses are received.
Getting millions of people vaccinated, in order of priority, is a big logistical challenge for states. As a result, there’s often a delay between when states receive their federal shipments of vaccines and when they get all the shots into people’s arms.
The speed of vaccination has improved since December, but there are still millions more doses distributed to states than have been administered to people.
States receive weekly vaccine allocations from the federal government based on their total adult populations. Each state has its own plan for how to get those vaccines out to its residents — through county health offices, hospital systems, pharmacies, mass vaccination sites and mobile clinics — and some states are using up their supplies more quickly than others.
According to the CDC data powering NPR’s tracker, West Virginia and North Dakota are making the most efficient use of the vaccines they receive and have gotten more than three-quarters of those doses into arms.
Some state officials have argued that the CDC figures don’t accurately represent how efficiently they are administering the vaccine doses they receive. The CDC says its data may reflect a reporting lag of up to five days.
President Biden has declared a goal of getting 100 million shots into arms in the first 100 days of his administration — an effort that stretches from late January through April.
To speed up the effort to get the U.S. population vaccinated, Biden says the country needs more vaccine supply from manufacturers and more efficiency from states.
The Biden administration is working out a deal to purchase an additional 200 million vaccine doses from Pfizer and Moderna, to be delivered this summer, and it plans to use the Defense Production Act to help smooth other bottlenecks, such as limited supplies of syringes or protective gear.
Biden promised to provide states with more reliable projections of the vaccine supply weeks ahead of time, to help them plan. He has also announced plans to increase the number of vaccinators and to blanket the nation with thousands of new locations where people can go to get vaccines, such as local pharmacies and vaccination sites supported by the Federal Emergency Management Agency.
Selena Simmons-Duffin, Ruth Talbot, Thomas Wilburn and Carmel Wroth contributed to this report.