A Kaiser Family Foundation report warned this week that the U.S. is approaching a 'tipping point': most people who were eager to get vaccinated already have been.
As of Friday, just shy of 42 percent of Americans - and nearly 53 percent of adults 18 and older - have had at least one dose of vaccine.
More than 35 percent of adults are fully vaccinated, or about 27.5 percent of the population.
Some 20 percent of the U.S. population is considered 'vaccine hesitant.' It's not entirely clear what is driving the current drop-off in daily vaccination rates ahead of the U.S. reaching 80 percent of eligible people getting vaccinated - but it seems to be widespread.
After rising to more than three million a day for at least a week, the seven-day rolling average of daily vaccinations is now below that figure, according to data from both Bloomberg and the CDC.
Some of the sites, like a mass vaccination site at Cal State in Los Angeles, California, were only slated to be open for an eight-week window after being installed by the Federal Emergency Management Agency (FEMA).
But others, like a mass vaccination site in Summit County, Colorado, are closing voluntarily and earlier than expected due to 'decreased demand' for vaccines.
Closures are also happening in Ohio, Nevada, Florida, Texas and California.
Meanwhile, officials in Kansas and Mississippi are asking federal officials to send them less vaccine.
All of these states are seeing declines in the number of vaccinations being given a day.
In most of these locations - and nationwide - daily Covid infections have fallen precipitously since the vaccine rollout picked up pace in January.
But in recent weeks, those declines have slowed, in a similar trend to the pace of vaccinations. Some places have even seen moderate increases.
In Ohio, where a mass vaccination site in Mercer County is set to close on May 7, the New York Times reported.
Officials there told the times that just 27 percent of adult residents of the county have had at least their first doses.
With fewer than 40 percent of people in Ohio partially vaccinated and less than 30 percent of its population fully vaccinated, most people in Ohio are still vulnerable to infection, and vaccinations have fallen off over the course of the month
But slots for vaccinations just aren't filling up.
The mass vaccination's appointment times were booked up within two hours of becoming available in the early days of the rollout.
Now, fewer and fewer of the 400 timeframes it offers a day are being used.
'It wasn't fair to ask our volunteers to keep showing up there when they weren't being fully utilized - they like to keep busy,' Jason Menchhofer, the county's health administrator told the Times.
Meanwhile, new daily infections in Ohio have increased slightly since mid-March.
Then, the Midwestern state, which has been a hotbed for anti-mask protests, was seeing about 1,500 new infections a day, according to Johns Hopkins data.
By April 11, its seven-day rolling average of cases had risen to more than 2,100 a day.
In the past week, daily infections dipped again to 1,600. But with fewer than 40 percent of people partially vaccinated and less than 30 percent of its population fully vaccinated, most people in Ohio are still vulnerable to infection.
After rising consistently to 1.8 million vaccinations a day for four weeks, last week just 1.3 million shots were given in Texas
In Texas, a vaccination site in Galveston is closing down.
After rising consistently to 1.8 million vaccinations a day for four weeks, last week just 1.3 million shots were given in Texas.
So far this week, only 575,000 shots have been given in the Lone Star State. It's unlikely that enough shots will be given before the week is out to equal the previous week's vaccinations.
And daily infections increased in Texas this week, to a seven-day rolling average of nearly 4,300 on Thursday - up from 3,371 a week earlier.
In most counties in Texas, between 18 and 22 percent of people are considered 'vaccine hesitant,' according to CDC data.
About half of Texas's population is vaccinated with at least one dose - suggesting it may be approaching its point of diminishing returns on vaccination campaigns.
Nevada's daily vaccinations have tanked this week, falling to just 19,000 a day on average yesterday, compared to the peak of nearly 24,000 a day on April 15
Las Vegas, too, is shutting down one of its sites too.
Nevada's daily vaccinations have tanked this week, falling to just 19,000 a day on average yesterday, compared to the peak of nearly 24,000 a day on April 15.
And Mississippi officials have asked the federal government to send small packages of vaccine so that they can be shipped to their respective clinics with less waste, according to the Huffington Post.
This week's vaccine supply dipped amid the 11-day pause on distribution of Johnson & Johnson's vaccine - but most states have not used all of their supply.
On Thursday, 8,555 shots were administered in the state, according to the Kansas Department of Health and Environment's data. That's only about half as many doses as were given the previous Thursday
Some experts worried that the pause - which was lifted on Friday night - has already fueled an increase in skepticism about vaccines in general, despite the U.S. health officials' deeming it safe and the risk of blood clots extremely low.
Notably, the investigation into blood clots linked to the J&J vaccine also looked into rates of clots after vaccination with Moderna's or Pfizer's shots. No blood clots were linked to either of the two mRNA shots.
'I do feel like there has been more hesitancy across the board since [the pause],' Corinth, Mississippi, pharmacist Austin Bullard told the Huffington Post.
And Kansas officials told the Huffington Post they have turned down shipments of Covid vaccine at least twice in the past month.
So far, 37.5 percent of Kansas residents have been vaccinated with at least one dose of vaccine. Daily rates there are falling off, too.
On Thursday, 8,555 shots were administered in the state, according to the Kansas Department of Health and Environment's data.
That's only about half as many doses as were given the previous Thursday.
'It is kind of stalling. Some people just don’t want it,' said Stacey Hileman, a nurse with the health department of Decatur County, a rural part of Kansas told the Huffington Post.
She said only about a third of people there have gotten their first dose.
And in some parts of small-town Mississippi, the first shipments only just arrived this month - to very little fanfare from residents.
Pharmacist Robin Jackson told HuffPo she had to throw out more vaccine than she administered, because her community just wasn't interested.
'Nobody was coming,' she told the outlet.
'And I mean no one.'