The White House launched a week-long blitz to encourage vaccination against COVID-19 this weekend, 1 week before the Fourth of July holiday, which the president has said will mark the country's independence from the pandemic.The administration had hoped 70% of Americans over age 18 would have received at least one dose of COVID-19 vaccine by Jul 4, but last week officials said they miss that mark.Now, top officials from the administration and even celebrities are being used to court what the Associated Press calls the "moveable middle," roughly 55 million unvaccinated American adults, many under age 30.These people are considered persuadable and open to the idea of vaccination but have not made it a priority.