It Might Be Time to Give Up on 'Herd Immunity'

For more than a year now, health authorities have been preaching the idea of "herd immunity" in regard to COVID. But it now appears that goal is out of reach for the foreseeable future and perhaps permanently, reports Apoorva Mandavilli in the New York Times. Two main factors are at play—ever-evolving mutations and the estimated 30% of the US population that wants no part of a vaccine. Even if the latter percentage shrinks, however, herd immunity is likely to remain elusive. But that doesn't necessarily mean a doom-and-gloom scenario. Among scientists and public health experts, a consensus is emerging that "the virus will most likely become a manageable threat that will continue to circulate in the United States for years to come, still causing hospitalizations and deaths but in much smaller numbers," writes Mandavilli.

That message is a tricky one, however, because it could cause people on the fence about a vaccine to skip it with a what's-the-point logic. On the other hand, the more people that get vaccinated and thus develop immunity, the more manageable the annual risk becomes, say health experts in the story. One factor is that the concept of herd immunity has much gray area, explains a post at Johns Hopkins. Its basic definition: "When most of a population is immune to an infectious disease, this provides indirect protection—or population immunity (also called herd immunity or herd protection)—to those who are not immune to the disease." Generally, it kicks in when 50% to 90% of a population is immune, but there's no "magic" number because of a slew of factors, including the virus' evolution. And that's especially true with a new disease such as COVID. Read the Times' entire piece. (More COVID-19 stories.)