The White House on Tuesday acknowledged it will not meet its goal of having 70 percent of all American adults receive at least one dose of a coronavirus vaccine by July 4, a rare setback for a president who has put the nation’s recovery from the pandemic at the center of his agenda.

It will be the second time the administration will miss a goal related to the pandemic — in part because it has repeatedly set objectives that are deliverable. Officials also indicated Monday that President Biden is likely to miss his target of shipping 80 million vaccines overseas by the end of the month, blaming it on logistical challenges.

The acknowledgement of a setback on Tuesday comes as the pace of U.S. vaccinations has dramatically fallen off, a worry to public health experts who say the nation must be wary of COVID-19 variants that could take hold in parts of the country.

Officials on Tuesday warned the delta variant is extremely transmissible, can be much more severe and poses a threat to unvaccinated young people.

“The delta variant is currently the greatest threat in the U.S. to our attempt to eliminate COVID-19," Anthony Fauci, the nation’s leading infectious diseases expert, said Tuesday. “Good news: All vaccines are effective against the delta variant. Conclusion: We have the tools, so let's use them and crush the outbreak.”

Yet while Tuesday was clearly a disappointment, it also comes as life in the United States rapidly returns to normal, with people going to summer blockbusters and baseball stadiums announcing they will fill to capacity this summer.

The White House cast the missed objective in positive terms, with White House coronavirus response coordinator Jeff Zients telling reporters it would take “a few extra weeks” to reach Biden's original marker.

“This is amazing progress and has our country returning to normal much sooner than anyone could have predicted,” Zients said Tuesday. “Where the country has more work to do is particularly with 18- to 26-year-olds. The reality is more younger Americans have felt that COVID-19 is not something that impacts them and they’ve been less eager to get the shot.”  

Zients acknowledged the U.S. would also fall short of having 160 million Americans fully vaccinated by Independence Day. According to the Centers for Disease Control and Prevention, about 150 million Americans are fully vaccinated.

“We will hit 160 million Americans fully vaccinated no later than mid-July,” he vowed.  

White House officials described Biden’s July 4 goal as aspirational and a way to provide incentives for people to get vaccinated so they can gather with family and friends.

They also announced a new goal: making sure adults over the age of 27 receive at least one shot by Independence Day.

Zients said that the U.S. has partially vaccinated 70 percent of adults aged 30 and older and is on track to reach people aged 27 and older after data from the July 4 weekend is counted.

The White House has not yet outlined new strategies it plans to deploy to reach younger adults who haven’t gotten vaccinated, but White House press secretary Jen Psaki said that officials would build on efforts already underway to reach this age group. She pointed to an ongoing college vaccine challenge and business incentive programs, like Microsoft giving away free Xbox consoles through the Boys and Girls Clubs of America.

“Our focus from the beginning has been continuing to redouble our efforts among demographics and groups where we need extra assistance,” Psaki said, before acknowledging there are limits to what the administration can do. “Ultimately, it is going to be up to individuals to decide if they want to get vaccinated.”  

Jen Kates, a senior vice president at the Kaiser Family Foundation, said she thinks younger people will be easier to convince than other holdouts. Still, she said that effort will fall largely on state and local officials rather than federal.

“What that requires is a ground game effort that is very intense. It's not usually something that a federal government does. It's certainly something our federal government can support by helping communities do that work, but it really is down to the almost old fashioned door-to-door kind of campaign,” Kates said.

Anand Parekh, chief medical adviser at the Bipartisan Policy Center, said that the most important data points of the vaccination program are the steep declines in daily cases to about 10,000 and daily deaths to about 300.  

Indeed, the White House is planning to celebrate that progress by hosting some 1,000 first responders, essential workers and military members on the South Lawn for an Independence Day celebration on July 4.

Parekh said the message to younger American adults should be threefold: reminding them of the threat from new variants, communicating that vaccinations are the key to getting back to normal life and stressing that vaccines protect others who are vulnerable around them but unable to get vaccinated.  

“We cannot stop; we need to do more particularly given the delta variant with its high transmissibility increasing across the country,” he said.  

Biden and other officials are crisscrossing the country to convince hesitant or unwilling Americans to get vaccinated as part of a “month of action” in June.

Despite promotions like lotteries, sports tickets and college scholarships, vaccination rates have lagged considerably, especially in the South and the Midwest.  

According to the Kaiser Family Foundation, 13 percent of all U.S. adults currently say they have no intention of ever getting vaccinated.

Only 16 states and Washington, D.C., have vaccinated 70 percent or more adults with at least one shot. Four states — Mississippi, Wyoming, Alabama and Louisiana — have vaccinated less than 50 percent of their populations with at least one dose.

First lady Jill Biden was in two Southern states, Mississippi and Tennessee, to tour vaccination sites on Tuesday. President Biden is scheduled to travel to North Carolina as part of the vaccination push later this week.  

Fauci on Tuesday warned about the threat of “localized surges” in areas with low vaccination rates.  

“There is a danger, a real danger, that if there is a persistence of a recalcitrance to getting vaccinated that you could see localized surges,” Fauci said during a White House briefing.

However, he emphasized: “All of that is totally and completely avoidable by getting vaccinated.”

Officials said that the Biden administration will continue to take steps to make vaccines more accessible, incentivize vaccinations and answer questions from wary Americans in the coming months.  

“We’re not going to let up. I know July 4 is an important deadline, but this continues long after July 4,” said U.S. Surgeon General Vivek Murthy. “We’re not going anywhere.”