As supply outstrips demand and the pace of U.S. COVID-19 vaccination slows down, President Biden on Tuesday announced a new goal: to vaccinate 70 percent of American adults by July 4.
It won’t be easy: Polling suggests that fewer than 65 percent of adults are either vaccinated already or eager to get a shot as soon as possible. But even if vaccinators do manage to hit Biden’s Independence Day target, the U.S. will still have a long way to go before it achieves the kind of lasting protection known as herd immunity — that is, the point when an estimated 75 to 90 percent of all Americans regardless of age