The blueprint is indeed there—achieve herd immunity and this coronavirus pandemic that has upended millions of lives over the past year can finally be toppled.
Reaching that goal, however, is easier said than done.
The nationwide vaccine rollout has been painfully slow and new coronavirus variants that have surfaced in the United Kingdom, Brazil, and South Africa could create a new wave of infections, even in people who have been vaccinated or previously exposed.
Such an occurrence, which we are already witnessing here in the early stages in the United States, could slow the progress toward herd immunity—an approach that aims to have enough people within a population become immune to a disease, often through vaccination or natural infection, to make its spread unlikely. As a result, the entire community is protected, even those who are not themselves immune, according to Harvard Medical School.
In addition, the percentage to achieve that important milestone has fluctuated over the course of the ongoing pandemic. For example, White House coronavirus advisor Dr. Anthony Fauci recently contended that the percentage of the population that would need to be vaccinated against the novel coronavirus in order to reach herd immunity would range “between 70 and 85 percent.”
Previously, the director of the National Institute of Allergy and Infectious Diseases said 70 to 75 percent.
“We have to realize that we have to be humble and realize what we don’t know. These are pure estimates and the calculations that I made, 70 to 75 percent, it’s a range. The range is going to be somewhere between 70 and 85 percent,” Fauci said in an interview on CNN’s State of the Union.
“I made a calculation that COVID-19, SARS-CoV-2, is not as nearly as transmissible as measles. Measles is the most transmissible infection you can imagine. So, I would imagine that you would need something a little bit less than the 90 percent, that’s where I got to the 85.”
He later added: Everyone has to be “honest and humble, nobody really knows for sure, but I think 70 to 85 percent for herd immunity for COVID-19 is a reasonable estimate. And in fact, most of my epidemiology colleagues agree with me.”
Dr. Wes Van Voorhis, professor of allergy and infectious diseases at the University of Washington and director of the Center for Emerging and Re-emerging Infectious Diseases, contended that herd immunity could potentially be achieved by the end of this year.
However, if “it’s really more than 80 percent, it’s going to take longer,” he said. “The percentage goes higher if a virus is transmitted more easily. So, if the mutant viruses circulating in the United Kingdom or South Africa really transmit easier, and they become widespread here, then the percentage to achieve herd immunity becomes higher.”
Fauci said that he sees that eventually happening to the novel coronavirus as well. When a large portion of the U.S. population gets inoculated, it will naturally establish an “umbrella” of immunity to the virus.
“That would be able to protect even the vulnerable who have not been vaccinated, or those in which the vaccine has not been effective,” the nation’s top infectious disease expert added.
Ethen Kim Lieser is a Minneapolis-based Science and Tech Editor who has held posts at Google, The Korea Herald, Lincoln Journal Star, AsianWeek, and Arirang TV. Follow or contact him on LinkedIn.