When I started medical school nearly fifty years ago in 1975, natural immunity was a well-recognized concept. It was not controversial; it was proven scientific fact.
For reasons that remain obscure, the scientific community was slow to acknowledge this fact in the wake of the Covid pandemic. For nearly three years, public-health officials dismissed the same understanding in their efforts to promote new vaccines for everyone, whether you had already had Covid or not. It seemed that politics was overwhelming scientific knowledge, regardless of how many times we heard, “we only follow the science.”
Much of the opposition to natural immunity was associated with those who pushed for lockdowns. The scientific community pushed back in the Great Barrington Declaration (GBD), which was written by three world-renowned epidemiologists and immunologists from Stanford, Harvard, and Oxford. In autumn 2020. Over 936,000 epidemiologists and physicians have signed this document, acknowledging the effectiveness of natural immunity.
Finally, albeit much too late, this is changing. The Lancet medical journal this month published a review of 65 studies that concluded prior infection with Covid – i.e. natural immunity – is at least as protective as two doses of mRNA vaccines. Allysia Finley, writing for The Wall Street Journal, says the only thing surprising about that was that the study made the mainstream press.
“Immunity acquired from a Covid infection is as protective as vaccination against severe illness and death, study finds,” NBC reported on February 16. The study found that prior infection offered 78.6% protection against reinfection from the original Wuhan, Alpha or Delta variants at 40 weeks, which slipped to 36.1% against Omicron variant. Protection against severe illness remained around 90% across all variants after 40 weeks. These results exceed what other studies have found for two and even three mRNA doses.
This news wasn’t fit to print until experts at the University of Washington confirmed it in a leading – and left-leaning – journal. The Lancet has a storied history of controversial publications including the debunked theory that measles vaccine causes autism.
Finley says The Lancet study’s vindication of natural immunity fits a pandemic pattern. The public-health clerisy rejects an argument that ostensibly threatens its authority; eventually it’s forced to soften its position in the face of incontrovertible evidence; and yet not once does it acknowledge its opponents were right in the first place. The supposition that prior Covid infection could protect against future illness was deeply rooted in immunology before studies bore it out. Those who dismissed natural immunity argued it wasn’t known how long protection against reinfection would last. That’s true, but we still don’t know exactly, and it seems to vary by person and variant. This is no surprise since we all have our own different levels of immunological competence.
The fact is that all of us are exposed to viruses and bacteria every day. Over their lifetimes people are frequently reinfected with viruses that cause respiratory illnesses, including other coronaviruses (like the common cold). But healthy people rarely get severely ill with a virus to which they’ve already been exposed. Infections generate antibodies in our blood and the membranes of the upper respiratory tract that prevent reinfection in the short-term. They also generate and train B and T white blood cells that prevent serious illness after antibodies wane (known as cellular immunity).
Repeat exposures train our immune systems to live with and fight off viruses as they become endemic in a sort of “peaceful coexistence.” Covid is moving from a pandemic to an endemic, much like influenza, and we will learn to live with it just as we have influenza. The GBD called for a new pandemic strategy with a focus on protecting the elderly and vulnerable while letting those at low risk for severe illness “live their lives normally to build up immunity to the virus through natural infection.” The aim was to minimize deaths and social harm until we reached herd immunity. While the goal of herd immunity proved elusive as the virus mutated, the declaration’s central premise was always correct: “As immunity builds in the population, the risk of infection to all – including the vulnerable – falls.” This is precisely what has happened over the past three years. Vaccines helped mitigate severe illness while people developed stronger natural immunity.
What about the future?
Although the virus has become more transmissible, we’ve built up what experts call an “immunity wall” that prevents it from spreading like a wildfire through a dense, dry forest, as happened in China after Beijing lifted its zero-Covid policy. The public-health clerisy worried that acknowledging natural immunity would encourage people to get infected or discourage them from getting vaccines. The first concern was unsupported, and the second was no reason to deny scientific reality. Public-health officials in the U.S. nonetheless dug in and refused to provide exemptions from vaccine mandates for those with natural immunity, as many European countries did. This has undermined the credibility of these public-health officials, which may prove harmful in the event of future pandemics.
To add insult to injury, tech companies suppressed discussion of natural immunity. Twitter flagged posts that claimed natural immunity was superior to vaccines as “misleading.” Facebook misinformation policy still restricts distribution of content that “implicitly discourages vaccination by advocating for alternatives” such as “natural immunity.” Amazon refused to publish books that didn’t agree with the decisions of the public-health officials.
Finley concludes, “The Lancet study could serve a useful political purpose by giving public-health officials cover to relax vaccine mandates, which in turn could reduce resistance to vaccines. But this would require the clerisy to concede its opponents were right.” Don’t hold your breath waiting for that to happen!
