Experts say that from a disease control perspective, the difference between 67 percent and 70 percent is insignificant. But from a political perspective, it would be the first time Mr. Biden has set a pandemic-related goal that he has not met. Mr. Biden has continually set relatively modest targets for himself and exceeded them, including his pledge to get 100 million shots in the arms of Americans by his first 100 days in office.
“The 70 percent target is not a hard and fast number; not hitting it exactly does not mean the sky is falling,” said Jen Kates, director of global health & H.I.V. policy at the Kaiser Family Foundation. “On the other hand, it has symbolic importance. There has been a lot of emphasis on getting to that point and not hitting it is a reminder of how difficult the remaining stretch is going to be.”
In a speech at the White House on May 4, Mr. Biden said he was launching a new phase in the fight against the coronavirus, with a goal of at least partly vaccinating 70 percent of adults by Independence Day. He made a personal plea to all of the unvaccinated: “This is your choice. It’s life and death.”
When asked about the July 4 deadline on Thursday, Jeffrey D. Zients, the White House coronavirus response coordinator, avoided saying specifically that the nation would reach the 70 percent threshold by that date.
“We’ve made tremendous progress,” Mr. Zients said. “Hundreds of thousands of people are continuing to get their first shots each day, and we’re going to get to 70 percent, and we’re going to continue across the summer months to push beyond 70 percent.”
Speaking to students at a Covid vaccination mobilization event at Clark Atlanta University in Georgia on Friday, Ms. Harris warned of the dangers of misinformation and framed the decision to get vaccinated as a way to take power back from the virus.
There are people who “may have heard things that aren’t quite true,” she said. “Let’s arm ourselves with the truth. When people say, it seems like this vaccine came about overnight, no it didn’t. It’s the result of many many years of research.”
Annie Karni contributed reporting.