Pandemic Endgame: Redefining the Herd Immunity Goal

"Early in the pandemic, when vaccines for the coronavirus were still just a glimmer on the horizon, the term 'herd immunity' came to signify the endgame: the point when enough Americans would be protected from the virus so we could be rid of the pathogen and reclaim our lives," writes Apoorva Mandavilli, a reporter for The New York Times who focuses on science and global health, on May 3.

Now, more than half of adults in the United States [145.3 million per CDC as of May 3] have been inoculated with at least one dose of a vaccine. 

But daily vaccination rates ["about 2.29 million doses per day on average, about a 32 percent decrease from the peak of 3.38 million reported on April 13," according to The New York Times vaccine rollout tracker on May 3] are slipping, and there is widespread consensus among scientists and public health experts that the herd immunity threshold is not attainable — at least not in the foreseeable future, and perhaps not ever.

Two months ago many experts likened the U.S. position in the pandemic to a battle between virus variants and vaccines, as if one would emerge a winner. Mandavilli writes that a new consensus is emerging, one that entails living with the virus.

It is already clear, however, that the virus is changing too quickly, new variants are spreading too easily and vaccination is proceeding too slowly for herd immunity to be within reach anytime soon.

“The virus is unlikely to go away,” said Rustom Antia, an evolutionary biologist at Emory University in Atlanta. “But we want to do all we can to check that it’s likely to become a mild infection.”

Politico supported the endemic end game scenario in an article framing the pandemic challenge facing President Joe Biden in his next 100 days published just a few days before the Times' piece.

"[C]ontainment, not eradication, is the most realistic goal: Public health experts say the coronavirus is here for the long haul," wrote health care reporter, Dan Goldberg, and health care editor, Joanne Kenen on April 30.

Now, the challenge for Biden, his response team and state health officials will be managing the rolling series of outbreaks possibly driven by more dangerous virus variants, while avoiding the wishful thinking of the Trump administration, which downplayed the disease's lethality.

Not all experts agree

Dr. Ashish Jha, dean of the Brown University School of Public Health, expressed some skepticism on the notion that herd immunity is not achievable.

"We don't know if it's true," he told CNN New Day hosts John Berman and Brianna Keilar on May 3, but he did acknowledge that it would be "unfortunate" if the country weren't to reach herd immunity levels.

"At herd immunity levels, you really don't have to have any restrictions at all and the virus remains in check," said Jha.

"But that said, the experience from Israel is that once you get to about 50-55% of the population vaccinated, which a few states have now hit in the U.S., you really see case numbers plummet. So we may not get to zero, we probably won't, but if we can get infections under very low levels, most of us can get back to our lives in normal ways. I think we can probably live with that.

"With around 60 percent of its population vaccinated, Israel has managed to almost fully reopen its economy and crush the number of coronavirus cases and deaths to nearly zero," wrote German Lopez for Vox in an endgame article referencing Mandavilli's piece.

The country still has some requirements in place — particularly indoor masking and vaccine passport requirements — but it’s much closer to normal than it could afford to be, with any guarantee of safety, just months ago.

Fauci gets last word

The nation's foremost public health expert, Dr. Anthony Fauci, appeared to agree with Jha.

“People were getting confused and thinking you’re never going to get the infections down until you reach this mystical level of herd immunity, whatever that number is,” he told Mandavilli.

“That’s why we stopped using herd immunity in the classic sense,” he added. “I’m saying: Forget that for a second. You vaccinate enough people, the infections are going to go down."

Related in Planetizen:

• The Pandemic's Next Phase in the U.S.: When Vaccine Supply Exceeds Demand, April 22, 2021
• Will Israel Show Us the Way Out of the Pandemic? February 14, 2021
• Post-Pandemic: Living with COVID, January 31, 2021
• Pandemic Endgame: The Goalposts are Moving, December 30, 2020
• Pandemic Endgame, May 18, 2020