President Joe Biden took a cautious victory lap Friday in his quest to bring the COVID-19 pandemic under control, announcing that 300 million vaccine shots have been administered in the 150 days since he took office.

Biden credited scientists, companies, the American people and his whole-of-government effort. The president noted that the widespread vaccination campaign had set 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% of American adults at least partially vaccinated by July Fourth, in a little over two weeks.

Overall, about 168 million American adults, or 65.1% of the U.S. population 18 years and older, have received at least one dose of the COVID-19 vaccine as of Friday, according to the Centers for Disease Control and Prevention.

The pace of new vaccinations in the U.S. has dropped significantly from a high of nearly 2 million per day about two months ago, jeopardizing Biden’s ability to hit the 70% 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 U.S. 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 U.S. Sen. Raphael Warnock.

Harris also spoke at a COVID-19 vaccination mobilization event at Clark Atlanta University, a historically Black school. She told students they “have the power to end this pandemic” by giving people information about the multitude of resources, such as free car rides and child care, that are available to help them get vaccinated.

In Fulton County, Georgia, where Atlanta is located, 49% of residents have received at least one shot. Statewide, it is 42%, Harris said.

“Getting vaccinated is about building the power of community,” she said. “Getting vaccinated is about building the power of our country.”

The Biden administration insists that even if the 70% vaccination goal is unmet, it will have little effect on the overall U.S. 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.