Is Natural Immunity as strong as Vaccinated Immunity?

By John Munsell,Chief Executive Officer, Bizzuka

Throughout this COVID pandemic, there has been a lot of debate surrounding the topic of natural immunity versus vaccinated immunity. 

Some believe that only vaccinated immunity should be recognized and accepted in the workplace, on public transportation, in restaurants, and even in hotels and entertainment venues.

Others believe that their prior history of having COVID should serve as the equivalent of an “immune passport” rather than being forced to comply with a “vaccine passport.”

But is there science that can actually end this debate once and for all? 

And is there a scientific way for every individual to understand their own unique level of immunity when it comes to COVID-19?

The CDC study on natural vs vaccinated immune strength

The CDC recently published a study looking at COVID cases and hospitalization rates by vaccination status and previous infection in California and New York.

Over 32 million adults who had at least one COVID test were included in this study. These subjects were divided into four groups:

  1. Unvaccinated with no recorded history of COVID infection
  2. Vaccinated (at least 14 days out from their final dose) with no recorded history of COVID infection
  3. Unvaccinated with history of prior COVID infection
  4. Vaccinated with history of prior COVID infection

As you might expect, the study showed that between May and November of 2021, the unvaccinated group with no history of prior infection showed the highest infection and hospitalization rates. 

The CDC in the past stated that people who had been vaccinated had stronger levels of immunity than those with natural immunity (unvaccinated with a history of prior infection), citing studies involving 246 patients in Kentucky covering May through June of 2021 and a statewide study including 201,649 hospitalized patients from January through September of 2021. 

Those studies showed marginal but notable advantages in favor of vaccination; however, studies from Israel including 2.5 million people and a study from the Cleveland Clinic including over 153,000 health care workers showed the opposite results. 

And so the debate raged on.

After the emergence of the Delta variant, the CDC’s latest research now confirms the findings of the Israeli studies and the Cleveland Clinic studies, noting that immunity from prior infection with no vaccination (group 3) is significantly stronger than vaccinated immunity without a prior infection (group 2). The strongest levels of immunity were observed in patients who were both vaccinated and had a prior history of infection (group 4).

Hospitalization rates for group 3 were 55.3-fold lower and 57.5-fold lower in group 4. In other words, a prior history of infection lowers your chances of being hospitalized by more than 55x and adding a vaccine on top of that lowers your chances of being hospitalized by another 2x.

The results of this study, for all intents and purposes, confirms a 2021 Cleveland Clinic study concluding that vaccines were unnecessary in those who had been previously infected. The Cleveland Clinic summarized that "individuals who have laboratory-confirmed symptomatic SARS-CoV-2 infection are unlikely to benefit from COVID-19 vaccination, and vaccines can be safely prioritized to those who have not been infected before."

If we've learned anything about this pandemic so far, it's that COVID variants make this virus extremely unpredictable.

The Omicron variant is an order of magnitude more contagious than any of its predecessors...

For instance, the Omicron variant is an order of magnitude more contagious than any of its predecessors, yet it appears to be far less lethal. That is very likely to be a byproduct of high vaccination rates combined with previous infection rates.

This can be confirmed, for the most part, by looking at the current high hospitalization rates of unvaccinated individuals without a prior history of infection. 

As new variants emerge, we can expect to see these numbers continue to change. The question is… in which direction?

Recognizing natural immunity alongside vaccinated immunity in your workplace

So, how do you keep your employees, your students, your faculty, and your residents safe?

Now that all studies confirm its legitimacy and efficacy, shouldn't naturally acquired immunity be recognized as an alternative to a vaccine mandate?

To recognize one without the other means we have lost sight of the goal. The goal is to reduce sickness, hospitalizations, and deaths. Both sources of immunity are legitimate and scientifically proven pathways to the goal. 

But regardless of whether you, your co-workers, your employees, or your students have natural immunity or vaccinated immunity, how do you as the employer quantify and measure that in order to validate and ensure protection inside of your workplace or school? 

Immunity to or protection from COVID-19 is directly tied to your production of what are known as “neutralizing antibodies.”

Immunity to or protection from COVID-19 is directly tied to your production of what are known as “neutralizing antibodies.” These are a form of binding antibody that specifically block the SARS-CoV-2 spike protein from attaching to the cell and replicating.

Studies show that antibodies generated from either catalyst (vaccine or infection) will wane over time. Your body doesn’t want to burn the energy producing antibodies continuously, so its natural process is to slow down or eliminate the production of those antibodies until another virus invades.

And therein lies the challenge of trying to ensure safety and protection from the virus inside your organization. It’s easy to verify that someone has been vaccinated or has had a previous infection. But how do you know their unique level of protection is sufficient to protect them and others inside of your workplace or environment?

Standard IgG/IgM antibody tests measure all antibodies: both binding and neutralizing. Unfortunately, that’s not actionable information, which is why the CDC does not recommend them as guidance for safety or behavior. However, their guidance has changed dramatically over the past few months as new data regarding infection, vaccination, antibodies, and immune durability emerge.

Neutralization assays are starting to see more uses beyond testing vaccine efficacy and convalescent plasma antibody content for treatment.

What are neutralization assays and neutralizing antibodies?

Neutralization assays or neutralizing antibody tests are designed to semi-quantitatively and qualitatively measure your neutralizing antibodies (NAbs) expressed as a percentage of your overall antibodies. 

A high concentration of NAbs is known to protect people from getting COVID. The best test for assessing your concentration of neutralizing antibodies is known as a surrogate virus neutralization test, or sVNT, and perhaps the best and most accurate of those is the cPass® from GenScript.

The Anzu Immunity Profile is the first NAbs test on the market to not only include the cPass® assay, but to extend with additional assays to test for NAbs that are effective against the Delta variant as well as detecting exposure to the virus through an N-antibody assay. 

With the Anzu Immunity Profile, you know: 

  1. How well protected you are against the original or “wild type” SARS-CoV2 virus, 
  2. How well protected you are against the Delta variant, and
  3. If you’ve been recently exposed to the virus.
immune test

Furthermore, as an employer with access to Anzu’s Immunity Management System, you can monitor the immunity levels of everyone in your workforce.

Establish policies, procedures, and protocols around unique immune markers for each person.

That means you can establish policies, procedures, and protocols around unique immune markers for each person rather than implementing rules of thumb or one-size-fits-all guidelines that could actually do more harm than good. 

If you want to truly understand the science behind managing immunity using the Anzu Immunity Profile, catch the free “immunity score” webinar.

If you want more information about managing natural and vaccinated immunity in your organization or implementing an “immunity passport” rather than mandating a vaccine passport, schedule a call with us. We’ll be happy to walk you through the process and see if it’s right for you. 

If you’d like to become a testing center offering the Anzu Immunity Profile, let us know, and we’ll send you all the details.


The Immunity Score

THE Critical Metric for Keeping People Safe in the Workplace