Biden credited scientists, companies, the American people and his whole-of-government effort on the milestone. The president noted that 65 per cent of adults have received at least one shot, setting the stage for most Americans to have a relatively normal summer as businesses reopen and employers hire. 

“We're heading into a very different summer compared to last year,” the president said. “A bright summer. Prayerfully, a summer of joy.” 

But as Biden marks one milestone, he is in danger of failing to meet another: his target to have 70 per cent of Americans at least partially vaccinated by July Fourth, in a little over two weeks. 

The Centers for Disease Control and Prevention says 305 million vaccine doses had been administered as of June 1O. About 141.6 million people, or 42.6% of the U.S. population, have been fully vaccinated. 

The pace of new vaccinations in the US has dropped significantly from a high of nearly 2 million per day about two months ago, jeopardizing Biden's ability to hit the 70 per cent mark. 

The White House said its whole-of-government approach to the vaccination effort has put the virus in retreat, which in turn has brought COVID-19 cases, hospitalizations and deaths to their lowest levels in more than a year. But Biden noted in his remarks that some communities in states with lower vaccination rates are seeing cases and hospitalizations increase. 

The administration is in the middle of a monthlong blitz to combat vaccine hesitancy and the lack of urgency some people feel to get the shots, particularly in the South and Midwest. 

CDC Director Rochelle Walensky said Friday that she expects the delta variant of the coronavirus will become the dominant strain in the US. That strain has become dominant in Britain after it was first detected in India. 

During an appearance on ABC's “Good Morning America,” she told Americans who get their shots that “you''ll be protected against this delta variant.” 

As part of the administration's vaccination push, Vice President Kamala Harris traveled to Atlanta on Friday to tour a pop-up COVID-19 vaccination site at Ebenezer Baptist Church, where Dr. Martin Luther King Jr. was a pastor until his assassination in 1968. The current senior pastor is US Sen. Raphael Warnock. 

Harris also spoke at a COVID-19 vaccination mobilization event at Clark Atlanta University, a historically Black school. 

The Biden administration insists that even if the 70 per cent vaccination goal is unmet, it will have little effect on the overall US recovery, which is already ahead of where Biden said it would be months ago. 

Biden wants to celebrate Independence Day as a “summer of freedom” from the virus. 

Earlier this week, the White House announced plans to host first responders, essential workers and service members and their families on the South Lawn for a cookout and to watch the fireworks over the National Mall. 

More than 1,000 guests are expected for what will be one of the largest events of Biden's presidency.