Herd Immunity: Discussion of what happens if the U.S. can't reach it

Are we there yet? What happens if the U.S. can't reach herd immunity. Without herd immunity, the country will see localized surges. But even if we don't get there, experts say there's still reason for hope. Science

Herd immunity is often seen as the end game of the COVID-19 pandemic. This threshold is reached when the virus cannot easily spread because most people have built up immunity through vaccination or natural infection. Then, “the virus just can’t find anyone to infect,” says Monica Gandhi, a professor of medicine and infectious diseases expert at the University of California, San Francisco, and the threat fades.

Experts estimate that we’ll reach herd immunity for COVID-19 when 65 to 80 percent of the population is vaccinated—a number that seemed within reach in the U.S. once highly effective vaccines started being administered. But after peaking at a seven-day average of more than three million doses in early April, the rate declined, and the country is now administering an average of a million doses a day.

Amid a swirl of misinformation, distribution issues, and legitimate hesitancy, as of June 3, only 51 percent of Americans have received at least one shot, and just 41 percent are fully vaccinated.

On June 1, U.S. President Joe Biden announced that anyone in America can get a free round of beer from Anheuser-Busch if they get vaccinated. It’s one of the latest government incentives being offered to help meet his administration’s goal of getting 70 percent of adults at least partially vaccinated by July 4, a key milestone in the nation’s bid to reach herd immunity. Some states are also offering big lottery winnings, free iced coffee, or—in West Virginia—trucks and custom hunting rifles.

Still, other experts say it’s possible the U.S. will never reach herd immunity. In a recent Kaiser Family Foundation survey, 13 percent of U.S. adults said they will “definitely not” get a vaccine.

So what happens then?

Here’s what scientists have to say about where the U.S. stands now, what that means for the return to life as we once knew it, and why there’s still cause for hope even if we can’t hit the target number for herd immunity. ...