The United States was poised to soon surpass more than 200 million people fully vaccinated against the coronavirus.
According to the Centers for Disease Control and Prevention, 198 million people in the United States were fully vaccinated as of Saturday, accounting for almost 60 percent of the total population. More than 45 million had also received additional doses.
On Tuesday, the agency’s director, Dr. Rochelle Walensky, said that although health officials were encouraging those eligible to get boosters, the agency was not changing its definition of fully vaccinated to include boosters “right now.”
Many vaccination clinics and local officials are reporting long lines and delays in booking vaccination appointments, which experts said were the product of expanded eligibility for boosters and fears over the new Omicron variant, though much remains unknown about the new version.
Mitchel Rothholz, the lead for immunization policy at the American Pharmacists Association, said that pharmacies were moving more to an appointment-based model with the uptick in demand, similar to when vaccines were first rolled out and there was a crush to get them. This means that people wanting a vaccine may need to plan ahead and could have to wait a few more days.
“We’ve got to go to a system where we can manage expectations,” he said.
The United States still lags behind a range of nations, including Canada, China, France, Japan, Spain and Singapore, in terms of the percentage of the population that is fully vaccinated.
The Biden administration is trying to make getting vaccinated easier. In remarks on Thursday on how to fight the Delta and Omicron variants, President Biden said the government would create hundreds of family-vaccination clinics, one-stop shops for shots and boosters. Partners in a federal pharmacy program, including major chains like CVS and Rite Aid, will also make “family-based scheduling” available in the months ahead, according to the White House.
Since the emergence of the Omicron variant, the C.D.C. has strengthened its booster guidance, urging that everyone age 18 and older get one six months after a Pfizer or Moderna series or two months after a Johnson & Johnson shot.
Dr. Leana Wen, a public health professor at George Washington University, said there were some pockets of the country where vaccines were expiring because demand was low and others where lines were longer than they were a month ago because of greater demand.
But, she said, demand is likely to ease in a few weeks.
“Whenever there is a new recommendation, there are the early adopters who are extremely eager to want to get that booster right now,” she said, adding that “supply and demand will equilibrate in short order.”
Some states and counties have hosted mass-vaccination clinics to alleviate the burden on pharmacies and meet demand from residents.
Richard Clark, the director of emergency management for Bernalillo County in New Mexico, which includes Albuquerque, said the county had been running vaccination clinics that attracted about 300 or 400 people each time. Mr. Clark said he had heard about people driving from counties an hour away to get their vaccine, because they were worried about the upcoming holidays and the new virus variant.
“We decided, let’s just do a large one,” he said, “and our 1,000 slots were filled within probably a day and a half.”
Gov. Charlie Baker of Massachusetts said this week that demand for vaccines had skyrocketed after boosters became widely available.
“We are doing over 50,000 shots per day,” Mr. Baker said, according to Boston 25 News, “and if we can find a way to work with our local colleagues in local government, we will come up with ways to put more shots on the table.”