Having made its way through those who lined up eagerly to get vaccinated for COVID-19, the campaign to inoculate every American is now slowing down with surplus supply and open appointments appearing in pockets nationwide.

While 3 million shots a day are being administered, that’s down from a peak of 3.4 million. And only 75% of about 28 million doses being shipped out weekly will be used at the current pace. All of this suggests the vaccine effort is evolving, from the megasites that inoculated thousands a day toward a slower grind designed to reach the half of Americans who haven’t yet received a dose.

The new focus: Those who have been unable to sign up, are waiting to get a shot, or who have been reluctant or refused to be vaccinated. It’s a goal, health officials say, that requires different tactics involving smaller, more focused distribution.

“There’s going to be 20 doses there, 15 doses here and 600 over here as opposed to maybe thousands at a time getting vaccinated,” said Elke Shaw-Tulloch, a public health administrator at the Idaho Department of Health and Welfare, at a briefing Tuesday.

For weeks, U.S. officials have touted the faster pace of reported daily vaccinations, which on April 10 hit 4.6 million doses. That may end up being a peak as the campaign moves into a new phase where success is measured less by gaudy totals than by its ability to reach the remote and the hesitant.

It’s also likely to change other benchmarks. Early in the rollout, states touted — or bemoaned — the fact that they were using up almost every dose they received. Many reported that they had used more than 90%, and were running out of shots in many locations.

But as the federal government has directed more of the available vaccine to tens of thousands of pharmacies and other sites, the supply chain is likely to become less efficient, with more doses scattered around more places as standing inventory.

Health officials in New York City — where 3.3 million people, or half the population, have received at least one dose — are starting to see a change, said Dave Chokshi, the city’s health commissioner, in an interview Thursday.

The city knew this would happen at some point, he said. But it’s coming a few weeks earlier than expected. “We shouldn’t lose sight of the fact that this is a positive thing,” Chokshi said. “The fact that appointments are no longer as scarce as they used to be means that more people can access them.”

Idaho is using about 73% of the doses it receives compared to the national average of 80%, Shaw-Tulloch said. And the gap is increasing, reversing months of improvements after an initially slow national rollout. Almost half of Iowa counties declined some or all of the shots they were able to order this week because they don’t need them, Iowa Governor Kim Reynolds said on Wednesday. Wyoming’s health director published a letter this week urging residents to get vaccinated.

“There are challenges as we think about the next 50% of the population,” said Nirav Shah, director of the Maine Center for Disease Control and Prevention.

Shah broke the remainder of the eligible population into three groups: the “not able” — people who need help scheduling or accessing a vaccine; the “not now” — those with legitimate questions about safety or efficacy; and the “not ever” — vaccine refusers who will be harder to reach.

Many in the final two groups aren’t likely to be vaccinated through mass clinics meant to serve those with the motivation and ability to go to the front of the line. They will require one-on-one conversations in a doctor’s office, said Steven Stack, commissioner of the Kentucky Department for Public Health.

“These are the settings where we’re most likely to reach the remaining 50%,” said Stack.

Employers Pushed

President Joe Biden on Wednesday outlined a new push to get employers to help create incentives for workers to get vaccinated, and make sure they have paid time off to get the shots. “I’m calling on every employer — large and small, in every state — to give employees the time off they need, with pay, to get vaccinated,” Biden said.

In Apache County, Arizona, interest has slowed so much that the health department had plenty of shots from Moderna Inc. in the freezer to swap in for the Johnson & Johnson vaccine that health agencies halted last week. Nearly 58% of the county’s adults are now fully vaccinated, according to data from the Centers for Disease Control and Prevention.

About two-thirds of people in the county are part of the Navajo Nation, which received shots directly from the Indian Health Service. The tribe quickly vaccinated its members. The county health department called in reserve nurses to help administer shots to non-tribal residents. Then demand fell off.

“We’re always going to have a trickle effect,” said Preston Raban, director of the Apache County Public Health Services District. “We’ll always have vaccine available for people who call and want to come in.”

Landscape Varies

The landscape varies nationwide, and even within different parts of individual states, with some areas still struggling to meet demand.

Appointments in Whatcom County, Washington, for instance, still fill up within 15 minutes to a few hours, even when more than 1,000 slots are available, said Erika Lautenbach, director of the Whatcom County Health Department. About 38% of people in that area are fully vaccinated, according to CDC data.

Meanwhile, many states are starting to shift their strategies now that supplies are more plentiful.

Ohio Governor Mike DeWine recently announced the state would send shots to doctor’s offices. Surveys have shown even people skeptical about the vaccines would trust their own physician more than anyone else.

“Primary care physicians have always been a part of the planned distribution network for vaccines,” a spokeswoman for the Ohio Department of Health said in an email.. “And as supply has become more available, it was a natural expansion of our efforts to ensure Ohioans have access to vaccines.”