U.S. health officials say 4.4 million Americans have received the updated COVID-19 booster shot. The Centers for Disease Control and Prevention posted the count Thursday as public health experts bemoaned President Joe Biden's recent remark that 'the pandemic is over.'

The White House said more than 5 million people had received the new boosters by its own estimate, which accounts for reporting lags in states.

Health experts said it was too early to predict whether demand would match up with the 171 million doses of the new boosters the U.S. ordered for the fall.

'No one would go looking at our flu shot uptake at this point and be like, 'Oh, what a disaster,' ' said Dr. David Dowdy, an infectious-disease epidemiologist at Johns Hopkins Bloomberg School of Public Health. 'If we start to see a large uptick in cases, I think we're going to see a lot of people getting the [new COVID] vaccine.'

A temporary shortage of Moderna vaccine caused some pharmacies to cancel appointments while encouraging people to reschedule for a Pfizer vaccine. The issue was expected to resolve as government regulators wrapped up an inspection and cleared batches of vaccine doses for distribution.

'I do expect this to pick up in the weeks ahead,' said White House COVID-19 coordinator Dr. Ashish Jha. 'We've been thinking and talking about this as an annual vaccine like the flu vaccine. Flu vaccine season picks up in late September and early October. We're just getting our education campaign going. So, we expect to see, despite the fact that this was a strong start, we actually expect this to ramp up stronger.'

Some Americans who plan to get the shot, designed to target the most common omicron strains, said they were waiting because they either had COVID-19 recently or another booster. They are following public health advice to wait several months to get the full benefit of their existing virus-fighting antibodies.

Others are scheduling shots closer to holiday gatherings and winter months when respiratory viruses spread more easily.

Retired hospital chaplain Jeanie Murphy, 69, of Shawnee, Kansas, plans to get the new booster in a couple of weeks after she has some minor knee surgery. Interest is high among her neighbors, she said.

'There's quite a bit of discussion happening among people who are ready to make appointments,' Murphy said. 'I found that encouraging.'

Steady state

Biden later acknowledged criticism of his remark about the pandemic being over and clarified the pandemic is 'not where it was.' The initial comment didn't bother Murphy. She believes the disease has entered a steady state when 'we'll get COVID shots in the fall the same as we do flu shots.'

Experts hope she's right but are waiting to see what levels of infection winter brings. The summer ebb in case numbers, hospitalizations and deaths may be followed by another surge, Dowdy said.

Some Americans who got the new shots said they were excited about the idea of targeting the vaccine to the variants circulating now.

'Give me all the science you can,' said Jeff Westling, 30, an attorney in Washington, who got the new booster and a flu shot Tuesday, one in each arm. He participates in the combat sport jujitsu, so he wants to protect himself from infections that may come with close contact.

Meanwhile, Biden's pronouncement in a 60 Minutes interview broadcast Sunday echoed through social media.

By Wednesday on Facebook, when a Kansas health department posted where residents could find the new booster shots, the first commenter remarked: 'But Biden says the pandemic is over.'

The president's statement, despite his attempts to clarify it, adds to public confusion, said Josh Michaud, associate director of global health policy with the Kaiser Family Foundation in Washington.

'People aren't sure when is the right time to get boosted. 'Am I eligible?' People are often confused about what the right choice is for them, even where to search for that information,' Michaud said.

'Any time you have mixed messages, it's detrimental to the public health effort,' Michaud said. 'Having the mixed messages from the president's remarks makes that job that much harder.'

University of South Florida epidemiologist Jason Salemi said he's worried the president's pronouncement has taken on a life of its own and may stall prevention efforts.

'That soundbite is there for a while now, and it's going to spread like wildfire. And it's going to give the impression that 'Oh, there's nothing more we need to do,' ' Salemi said.

'If we're happy with 400 or 500 people dying every single day from COVID, there's a problem with that,' Salemi said. 'We can absolutely do better because most of those deaths, if not all of them, are absolutely preventable with the tools that we have.'