Biden credited scientists, companies, the American people and his whole-of-government effort.
"We're heading into a very different summer compared to previous year", the president said. "A bright summer. Prayerfully, a summer of joy".
Overall, about 168 million American adults, or 65.1% of the USA 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 USA has dropped significantly from a high of almost 2 million per day about two months ago, jeopardizing Biden's ability to hit the 70% mark. We didn't have the vaccine infrastructure or the people to administer the vaccines or the places where the people could get vaccinated.
Biden had set a goal of vaccinating at least 70 percent of USA adults with at least one dose by July 4, though the U.S.is not expected to reach that goal.
Concerned over the rising cases of coronavirus where the vaccination rate is lower, he said, "The truth is that deaths and hospitalizations are drastically down in places where people are getting vaccinated". Especially because of what experts are calling the 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 the Rev. Martin Luther King Jr. was a pastor until his assassination in 1968. Rochelle Walensky, the director of the Centers for Disease Control and Prevention, said the delta variant made up almost 10 percent of US cases this month, compared to 2.7 percent of all cases in May.
Harris also spoke at a COVID-19 vaccination mobilization event at Clark Atlanta University, a historically Black school.
The signatories claimed in the letter that Biden's "mental decline and forgetfulness have become more apparent over the past eighteen months", listing several gaffes that the president has dropped recently, particularly pointing at situations in which Biden appeared to have trouble remembering the name of his Defense Secretary or failed to recite the first line of the Declaration of Independence in March 2020.
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.