The rapid increase in coronavirus infections driven by the delta variant over the past month is turning the country’s attention back to the pandemic and threatening to subsume President Biden’s agenda — just as the White House and its allies hoped to move on from the virus and focus on promoting the administration’s other accomplishments.

Inside the White House, top officials are growing increasingly anxious about the state of the pandemic and are gravely concerned about the situation spiraling out of control in some areas of the country with low vaccination rates, according to two people who work in the administration and two others in close touch with the White House.

Biden’s team had always expected to see additional coronavirus outbreaks, but the White House assumed the increases in infections would be “mounds” and not “peaks,” according to one top administration official, who like others spoke on the condition of anonymity to reveal private discussions.

Officials are now looking at models that predict anywhere from a few thousand new covid cases to more than 200,000 every day in the fall. One new forecast also estimates the United States could see three times the number of daily deaths from the coronavirus by October compared to now. The current seven-day average is about 250 deaths per day.

The delta variant has become the dominant strain of coronavirus in the United States, resulting in a rise in infections and hospitalizations. (John Farrell/The Washington Post)

Stock markets have already shown jitters over the variant, with the Dow slumping more than 700 points Monday before rallying later in the week. Globally, hospitals are filling up — including in the United Kingdom, which is experiencing an outbreak so severe that the United States warned against traveling there.

“If you have hundreds of thousands of Americans getting sick, that’s problematic for any president,” said Cornell Belcher, who was one of former president Barack Obama’s pollsters. “It does become all consuming for the president — because he’s the president.”

More focus on covid leaves the president fewer opportunities to sell the stimulus package that Congress approved earlier this year or travel the country pressuring lawmakers to back his infrastructure plan. Other priorities that risk being squeezed include shoring up voting rights, a policing overhaul, gun control and new immigration rules.

Biden’s CNN town hall this week was dominated by questions about the virus — a marked change from his first formal news conference, during which the pandemic did not come up at all.

Americans are growing more concerned about the state of the pandemic. In an Axios-Ipsos poll conducted July 16-19, 39 percent of Americans said that returning to their pre-coronavirus life right now would be a risk, up from 28 percent in late June.

The White House has sought to place blame elsewhere, with Biden accusing social media platforms of “killing people” by allowing misinformation to spread on their platforms. And allies have pointed out that the biggest infections increases are coming in Republican-led states — another way of deflecting from the administration.

Top officials say Biden isn’t going to let up from his push for vaccinations and controlling the pandemic even he works to make a spending deal with Congress.

“Getting the pandemic under control [and] protecting Americans from the spread of the virus has been [and] continues to be his number-one priority,” White House press secretary Jen Psaki said Thursday. “It will continue to be his priority moving forward. There’s no question.”

One White House official, who was not authorized to speak publicly, said administration health experts don’t expect hospitalizations or deaths to reach the same levels seen during the height of the pandemic.

The White House has also been heartened that, in recent weeks, vaccination rates have risen faster than the national average in some states with high infection rates, such as Nevada and Florida, the person said.

Still, the delta variant surge is a serious enough threat that top White House officials and other administration officials are debating whether to urge vaccinated Americans to wear masks in more settings, people familiar with the discussion said this week.

Top White House aide Mike Donilon told reporters that the virus has “been a primary focus from the time he came into office and hasn’t let up.”

“He hasn’t taken his eye off the ball there,” Donilon said.

And he sought to cast Biden’s spending proposals as part of the covid response. “These investments that he’s proposing will make a big difference in terms of pushing forward,” Donilon said. “He has a lot on his plate and he’s fully focused on all of this.”

Still, the president’s allies and top advisers have also been clear that they want to draw attention to other parts of his agenda — including making a strong case for the infrastructure proposals via amped-up travel and events. In his call with reporters, Donilon walked through a slide show aimed at promoting Biden’s infrastructure proposals.

“When people focus on how this agenda is paid for, support for it actually increases,” Donilon said. “It also rises as they learn more and more about the individual components.”

Top officials at Unite the Country, a pro-Biden super PAC, warned donors and surrogates earlier this month that focus groups with swing-state voters revealed that even many Biden supporters know little about his accomplishments.

“There is a real lack of information about the specifics of the Biden agenda,” according to a memo from the super PAC that was obtained by The Washington Post.

“There is a need to communicate with voters, even among high-information Biden supporters,” according to the memo. “There wasn’t a ton of knowledge about the components of the Biden plans.”

The memo, issued before the delta variant spread widely, didn’t directly mention covid. But there was one nod to a possible political benefit of a raging virus.

Since 1992, the sitting president has avoided significant midterm losses just twice (in 1998 and 2002), and in both cases it was because the president “was able to harness energy around a national crisis to remain popular,” according to the memo.

Indeed, voters give Biden high marks for his handling of the coronavirus crisis, and they’re more comfortable with his performance there than on other issues such as his handling of the economy or immigration.

Biden consistently sees higher ratings on his handling of the pandemic than his overall approval. Sixty-six percent of Americans say he’s doing a “good job” handling the coronavirus, according to a recent CBS News-YouGov poll. In the same poll, 58 percent of respondents approve of his performance as president.

“If anything, when covid is not on the agenda — when people are not focused on covid — his numbers tend to settle a little bit because people think, ‘Who would be better on the next thing?’ ” said Celinda Lake, a Democratic pollster who did work for Biden’s presidential campaign.

Still, Republicans see the next phase of the pandemic as a potential weakness for the president.

“The biggest thing that the average person knew was that everything was going to be over by July 4,” said Corry Bliss, a Republican strategist. “Now we’re a couple weeks past July 4, and the message from the White House is, ‘We have no idea what’s going on.’ ”

Bliss said the White House “looks lost and message-less.”

“They declared mission accomplished and the new slogan should be mission incompetence,” Bliss said. “The only part of getting back to normal was the vaccine rollout which was a direct result of the Trump administration and Operation Warp Speed. It’s unclear that they’ve done a single thing to advance the ball on covid.”

The Biden administration will not reach its original vaccination goal for the Fourth of July. Surgeon General Vivek H. Murthy updates on the next phase. (Blair Guild/The Washington Post)

Biden targeted the Fourth of July as his goal for when the country would “begin to mark our independence from this virus,” as he put it in March, and Americans could safely gather in small groups.

In May, as millions of Americans were vaccinated, the CDC changed their guidance to say vaccinated people could shed masks in most circumstances. The mood at the White House was jubilant as the president and staff removed their masks and celebrated the country’s progress in curtailing the virus.

As July Fourth approached, however, administration officials nervously watched as the delta variant wreaked havoc in countries around the world.

The president still gave a victory speech of sorts on Independence Day, declaring “the virus is on the run and America is coming back,” but officials familiar with the planning of the event said the speech was toned down to reflect the uncertainty around the variant.

Biden’s overall low-key approach to the virus worries observers taking a longer view of his presidency.

Douglas Brinkley, a presidential historian, noted that Franklin Delano Roosevelt traveled “nonstop” when he was president, despite a physical disability. “Why can’t Biden be more mobile and out there talking to people? No president can be above the fray in a pandemic.”

Brinkley also said that Biden’s first six months in office became dominated by a swirl of non-covid issues, including voting rights and infrastructure. “There came a false sense of security on the covid front,” Brinkley said. “People will think in history that Biden needed to be doing regular addresses to the American public. That this was such a large emergency, with so many deaths on the line, that he needed to be beating the drum more forcefully.”

Biden may have a chance to rectify this stance in the fall.

Experts have cautioned that the delta variant — which first emerged in India and now represents more than 83 percent of U.S. coronavirus cases — is far more transmissible than prior strains of the virus, leading to a sharp uptick in new infections.

The daily average of confirmed coronavirus cases has roughly quadrupled in the past month, from about 11,000 per day in late June to 44,011 now, according to The Washington Post’s seven-day average of coronavirus cases. Variant-linked cases also have fueled a 59 percent increase in hospitalizations in Florida and a 76 percent increase in Louisiana in the past week, disproportionately among unvaccinated Americans.

“It is one of the most infectious respiratory viruses we know of and that I have seen in my 20-year career,” Centers for Disease Control and Prevention Director Rochelle Walensky told reporters on Thursday, urging holdout Americans to get vaccinated. Only about 49 percent of all Americans have been fully vaccinated against the coronavirus, according to The Post’s tracking.

CDC Director Rochelle Walensky on July 20 testified before the Senate Committee on Health, Education, Labor and Pensions about the Delta variant in the U.S. (The Washington Post)

The COVID-19 Scenario Modeling Hub, a research consortium that incorporates analysis from Johns Hopkins University, Columbia University and other academic teams, also released new projections this week that account for the delta variant’s potential spread. The models incorporate factors such as vaccination levels and the speed at which the virus is spreading.

Under one particularly dire projection, the resurgent outbreak would peak in October with roughly 240,000 new cases per day and 4,000 deaths across the United States — bleak numbers roughly on par with the outbreak that Biden inherited in January.

“While I think it’s possible things could get that bad, I don’t think it’s likely,” said Justin Lessler, a University of North Carolina professor who has helped coordinate the models. “We’d never reach that worst-case scenario, because we would react. We don’t just tend to sit there and wait to die.”

Lessler said that the research hub’s consensus projection is that cases will peak in October at around 60,000 cases per day, but he cautioned that projection was based on data collected before the recent surge of variant-linked cases.

“The last two weeks have been quite bad compared to where we were thinking,” Lessler added. “I worry, and maybe think, that it’s going to be slightly worse than our consensus projection based on trends.”

Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota and an epidemiologist who served on Biden’s coronavirus advisory board during the transition, said that he and his team had reviewed Kaiser Family Foundation data on how many Americans are still at risk for the spreading virus.

“We still come up with 100 million people in this country who have not been vaccinated, nor have they had covid-19” and retain lingering immunity, Osterholm said. “That is more than enough human wood for this coronavirus forest fire to burn. And that’s going to happen.”

Anne Gearan and Emily Guskin contributed to this report.