Federal health officials on Thursday sought to underscore progress the U.S is making in its fight against the COVID-19 pandemic – touting growing vaccination rates, even as officials acknowledged a new "summer surge" in parts of the country, fueled largely by low vaccination rates and the spread of the highly contagious delta variant.

What You Need To Know

  • The U.S. distributed more than 864,000 new COVID-19 vaccinations in the past 24 hours, White House officials said Thursday – marking its highest single-day average since Jul. 3

  • Officials touted the vaccine rate as evidence of U.S. progress against the COVID-19 vaccine – even as they acknowledged that some parts of the country are struggling to make headway in their fight against the virus

  • On Thursday, CDC Director Dr. Rochelle Walensky said the U.S. seven-day average of new COVID-19 cases has increased to an average of 89,463 new cases a day, a 43% increase from the previous week.

  • Seven states – Florida, Texas, Missouri, Arkansas, Louisiana, Alabama, and Mississippi – which have some of the lowest vaccine rates in the U.S., currently account for half of new cases and hospitalizations

The U.S. has recorded more than 864,000 new COVID-19 vaccines in the past 24 hours, officials said Thursday. The figure represents a significant positive development, which comes even as cases continue to surge in many parts of the U.S., including seven states with some of the lowest vaccination rates in the country.

“We’ve more than doubled the average number of people newly vaccinated each day over the past three weeks in the states with the highest case rates,” White House COVID-19 response coordinator Jeff Zients said Thursday. “Louisiana, Arkansas, Missouri, Alabama, Oklahoma and Mississippi are now vaccinating people at a pace not seen since April.”

Zients also cited progress in states like Tennessee, which reported a 90% increase in first shots over the past two weeks, and Georgia, which saw a 66% increase in shots during that same period.

"Clearly, Americans are seeing the impact of being unvaccinated and unprotected,” he said.

But Thursday's remarks from top U.S. health offiicals come amid a second surge in new COVID-19 cases and hospitalizations in parts of the U.S., which has prompted concern that the U.S. could be forced to re-adopt some of its former restrictions this fall.

On Thursday, CDC Director Rochelle Walensky said the U.S. seven-day average of new COVID-19 cases has increased to an average of 89,463 new cases a day, a 43% increase from the previous week. Hospitalizations and deaths have also increased by 41% and 39%, respectively.

"Across the board, we are seeing increases in cases and hospitalizations in all age groups," Walensky said. "Those at highest risk remain people who have not yet been vaccinated."

The new U.S. cases are heavily concentrated in states with some of the lowest vaccination rates in the country – Florida, Texas, Missouri, Arkansas, Louisiana, Alabama, and Mississippi.

Those seven states account for “roughly half of new U.S. cases and hospitalizations recorded in the past week, despite making up less than a quarter of the U.S. population combined,” White House COVID-19 response coordinator Jeff Zients said.

“Over the past seven days, patients in Florida and Texas have accounted for about one-third of new COVID-19 cases in the U.S., and more than one-third of new U.S. hospitalizations,” Zients said.

This sobering new statistic comes just days after President Biden sharply criticized several Republican governors, including Florida Gov. Ron DeSantis and Texas Gov. Greg Abbot, for their attempts to block localities and businesses imposing mask and vaccine mandates.

“If you’re not going to help, at least get out of the way of people trying to do the right thing,” Biden said Tuesday.

Florida on Wednesday reported its third day in a row of record-breaking COVID-19 hospitalizations, and the state’s seven day average of new cases was more than 17,750 – a 700 percent increase from the same time last month. Roughly 40% of the state's ICU beds are occupied, and several hospitals have opted to suspend elective surgeries and other non-emergency treatments.

The briefing comes just one week after the CDC updated its mask guidance to recommend that fully vaccinated people wear masks indoors in parts of the country where community transmission of the virus is "substantial" or "high." The CDC also recommended masks be worn by all students, K-12, when they return to classrooms this fall.

Walensky warned last week just how much more contagious the delta variant is: "To put this in perspective, if you get sick with the Alpha variant, you could infect about two other unvaccinated people. If you get sick with the Delta variant, we estimate that you could infect about five other unvaccinated people — more than twice as many as the original strain."

Asked about the possibility that COVID-19 could further mutate into a strain that is resistant to vaccines – a possibility health officials have warned about in recent days – Dr. Anthony Fauci, the White House's chief medical adviser, said "the easiest way to avoid" that scenario is "to get as many people vaccinated as quickly as we possibly can to not allow the virus to circulate in the community, giving it ample time to mutate."

"We have within our power to prevent that," he added

Appearing on ABC News' "Good Morning America" hours earlier, Fauci noted that the U.S. will see more variants that evade vaccines if the country does not get a handle on community spread.

"That will happen," Dr. Fauci told "GMA" anchor George Stephanopoulos, "if we don't get good control over the community spread, which is the reason why I and my colleagues keep saying and over again, it is very important to get as many people vaccinated as we possibly can."

"People who say, 'I don't want to get vaccinated because it's me and I'll worry about me, I'm not having any impact on anybody else,' that's just not the case," he added.

"And when you give it ample opportunity to mutate, you may sooner or later get another variant, and it is possible that that variant might be in some respects worse than the already very difficult variant we're dealing with now, which is a major reason why you want to completely suppress the circulation of the virus in the community," he said.

The Biden administration is also facing pressure to reopen international travel to non-U.S. residents in countries including China, India, Britain, and South Africa for the first time in more than a year.

It was reported Wednesday that the Biden administration taking steps toward requiring nearly all foreign visitors to the United States be fully vaccinated against the COVID-19. No timeline has been announced, however, and it is unclear whether the surge of the delta variant could upend those plans.

On Thursday, White House COVID-19 response coordinator Jeff Zients said the U.S. "will maintain the existing travel restrictions at this point," but says the administration is “working on” plans for how best to safely open up travel.