Guest column on the value of naturally acquired immunity

September 2021  news release (not peer reviewed)

More than 15 studies have demonstrated the power of immunity acquired by previously having the virus. A 700,000-person study from Israel two weeks ago found that those who had experienced prior infectionswere 27 times less likely to get a second symptomatic covid infection than those who were vaccinated. This affirmed a June Cleveland Clinic study of health-care workers (who are often exposed to the virus), in which nonewho had previously tested positive for the coronavirus got reinfected. The study authors concluded that “individuals who have had SARS-CoV-2 infection are unlikely to benefit from covid-19 vaccination.” And in May, a Washington University study found that even a mild covid infection resulted in long-lasting immunity.

The incorrect hypothesis that natural immunity is unreliable has resulted in the loss of thousands of American lives, avoidable vaccine complications, and damaged the credibility of public health officials. Given the recent mandate announcement by the White House, it would be good for our public health leaders to show humility by acknowledging that the hypothesis they repeatedly trumpeted was not only wrong, but it may be harmful. Let’s all come together around the mounting body of scientific literature and real-world clinical experience that is telling us not to require the full vaccine regimen in people who recovered from covid in the past. Public health officials changing their position on natural immunity, after so much hostility toward the idea, would go a long way in rebuilding the public trust.

September 2021  news release (not peer reviewed)

The findings suggest that natural immunity provides longer-lasting and stronger protection against infection, symptomatic disease, and hospitalization due to the Delta variant, compared with the protection of the Pfizer-BioNTech two-dose vaccine, the researchers conclude.

In addition, those with natural immunity exhibit additional protection against the Delta variant when given a single dose of the vaccine, according to the results.

The researchers are continuing to investigate the long-term protection provided by a third dose, or booster, of this vaccine.

August 2021  published research (peer reviewed)

This study describes the qualitative aspects of the Ab and memory B cell response in both vaccine-induced immunity as well as Immunity after natural infection.

Evidence suggests that Ab immunity to endemic seasonal CoVs and SARS-CoV wanes within a 2- to 3-year period in the majority of those previously infected [79132135], which represents a combination of lack of cross-protective immunity to mutating seasonal strains, rhythms in the circulation of different CoVs [136138], and loss of antibody-producing cells over time with ageing [139]. Several case studies of SARS-CoV-2 reinfection have been documented in the literature [140141], although it is not known at present whether these were caused by infection with a different strain, waning immunity or unique clinical features explained the occurrence. Indeed, early results indicate that the potency of engendered antibodies is generally reduced when faced with a new S variant strain [88142144], suggesting less effective but not abolished immunity due to changes in neutralizing antibody epitopes in S. This is similar to what has been observed for vaccines based on the original Wuhan, China strain [145148]. Neutralizing antibody titers after mild SARS-CoV-2 infection were reported to be comparable to those engendered by first-generation COVID-19 vaccines [149150].

September 2021  news release (not peer reviewed)

“Previously, there was a lot of concern that only those with severe COVID-19 produced strong antibody responses to infection,” said Charles Schuler, M.D., lead author of the paper and clinical assistant professor of allergy and immunology at Michigan Medicine. “We’re showing that people with mild bouts of COVID-19 did really well after their infection, made antibodies, and kept them.”

August 2021  pre-print  (not peer reviewed)

This analysis from Israel demonstrated that natural immunity affords longer lasting and stronger protection against infection, symptomatic disease and hospitalization due to the Delta variant of SARS-CoV-2, compared to the BNT162b2 two-dose vaccine-induced immunity. Notably, individuals who were previously infected with SARS-CoV-2 and given a single dose of the BNT162b2 vaccine gained additional protection against the Delta variant. The long-term protection provided by a third dose, recently administered in Israel, is still unknown.

August 2021   news release (not peer reviewed)

Vaccination produces greater amounts of circulating antibodies than natural infection. But a new study suggests that not all memory B cells are created equal. While vaccination gives rise to memory B cells that evolve over a few weeks, natural infection births memory B cells that continue to evolve over several months, producing highly potent antibodies adept at eliminating even viral variants.

The findings highlight an advantage bestowed by natural infection rather than vaccination, but the authors caution that the benefits of stronger memory B cells do not outweigh the risk of disability and death from COVID-19.

“While a natural infection may induce maturation of antibodies with broader activity than a vaccine does—a natural infection can also kill you,” says Michel C. Nussenzweig, the Zanvil A. Cohn and Ralph M. Steinman professor and head of Rockefeller’s Laboratory of Molecular Immunology. “A vaccine won’t do that and, in fact, protects against the risk of serious illness or death from infection.”

There are several potential reasons that memory B cells produced by natural infection might be expected to outperform those produced by mRNA vaccines, the researchers say.

It is possible that the body responds differently to viruses that enter through the respiratory tract than those that are injected into our upper arms. Or perhaps an intact virus goads the immune system in a way that the lone spike protein represented by the vaccines simply cannot. Then again, maybe it’s that the virus persists in the naturally infected for weeks, giving the body more time to mount a robust response. The vaccine, on the other hand, is flushed out of the body mere days after triggering the desired immune response.

Regardless of the cause, the implications are clear. We can expect memory B cells to undergo limited volleys of evolution in response to mRNA vaccines, a finding that may have significant implications for the design and rollout of booster shots. A booster with the currently available mRNA vaccine would be expected to engage memory cells to produce circulating antibodies that are strongly protective against the original virus and somewhat less so against the variants, Nussenzweig says.

“When to administer the booster depends on the object of boosting,” he says. “If the goal is to prevent infection, then boosting will need to be done after 6 to 18 months depending on the immune status of the individual. If the goal is to prevent serious disease boosting may not be necessary for years.”


Evidence for the superiority of natural immunity over vaccine-induced immunity continues to accumulate, and it should not be a surprise. This has been our common understanding for multiple viral diseases in the past, particularly so when there has previously been NO successful large-scale roll-out of a vaccine for coronaviruses.