» U.S. vaccination pace increases to 2 million doses a day into arms,

The average number of vaccine doses being administered across the United States per day topped two million for the first time on Wednesday, according to data from the Centers for Disease Control and Prevention. A month ago, the average was about 1.3 million.

President Biden set a goal for the country shortly after taking office to administer more than 1.5 million doses a day, which the nation has now comfortably exceeded.

Biden has also promised to administer 100 million vaccines by his 100th day in office, which is April 30. As of Thursday, 54 million people have received at least one dose of a COVID-19 vaccine. Johnson & Johnson’s oneshot vaccine was authorized for emergency use on Saturday, but those doses do not appear yet in the CDC data.

The milestone was yet another sign of momentum in the nation’s effort to vaccinate every willing adult, even as state and city governments face several challenges, from current supply to logistics to hesitancy, of getting all of those doses into people’s arms.

Mass vaccination sites across the country are opening up or increasing their capacity, in part to respond to the new influx of doses from Johnson & Johnson. In New York, Gov. Andrew M. Cuomo announced Thursday that three short-term mass vaccination sites will open in the state today. In Georgia, Gov. Brian Kemp announced five new sites will open on March 17.

The Federal Emergency Management Agency has recently helped open seven mega-sites in California, New York and Texas that are staffed with active-duty troops. In Chicago, a vaccination site at the United Center will open next week, with a capacity of 6,000 shots a day.

There have been some hiccups in the massive logistical challenge of distributing millions of doses across the country, with special requirements for storage and handling. In Texas, more than 2,000 doses went to waste over the past two weeks, according to an analysis by The Houston Chronicle. A majority of those losses were blamed on blackouts that swept the state in February, leaving millions of homes and businesses without power.