Immunity Debt: The Conspiracy Theory Elevated to Popular Pseudoscience That Is Making Children Sick

It is time to retire this dangerous and misleading concept and focus on the real science

The concept of “Immunity Debt” was adopted to explain global surges in respiratory virus illness during the 2022-23 cold and flu season. The problem is, it was only recently invented and there is no evidence that supports “Immunity Debt” as being responsible for our earlier and more severe respiratory virus seasons.

The American Association of Health Care Journalists stated the following in December of 2022:

• “Immunity debt” is not an established epidemiological term and is problematically being used to mean different phenomena. 

• The current caseload of flu, RSV and COVID-19 infections is not occurring because people’s immune systems were weakened from lack of exposure to pathogens during mask-wearing and social distancing.

• Accurate use of the term immunity debt (or in some cases is called “immunity gap”) refers to the idea that masking and social distancing temporarily held off infections, which are now occurring as population behavior allows the greater spread of pathogens.  

• A problematic aspect of using the term is its implication that a disease must be “paid back,” which is inaccurate.

• The best journalistic practice is not to use the term “immunity debt” at all except in clarifying how it’s being misused.

What they missed is the tremendous surge in respiratory virus infections does have a scientifically valid explanation: SARS-CoV-2 infection causes immune system dysfunction.

As we face another early increase in respiratory virus infections and heightened severity of these infections with “white lung syndrome” filling pediatric emergency rooms, finally, the hypothesis of “Immunity Debt” is finally falling flat.

The term “Immunity Debt” started in the shadowy realm of COVID-19 conspiracy theories as a justification for why people should not wear masks to avoid infection with respiratory viruses.

Note the wildly flawed logic of simultaneously proclaiming that masks don’t work but also work so well they cause “Immunity Debt”.

“Immunity Debt” surged in media popularity during the 2022-2023 winter respiratory virus season which was characterized by an early and massive surge of Influenza, RSV, and SARS-CoV-2 infections dubbed the “Triple-demic”.

Graphic of CDC data from NYTimes article Just How Bad Is the ‘Tripledemic’? By Amy Schoenfeld Walker Dec. 16, 2022.

“Immunity Debt” was an especially convenient explanation in that it ignored the dangers of repeat SARS-CoV-2 infection. Many were encouraged not to mask and proceed as if nothing was wrong, elevating the concept from conspiracy theory to popular pseudoscience taken as physician-backed fact by parents across the world.

Going into the 2023-24 respiratory virus season we again have an earlier and more severe multi-virus driven surge in viral infection.

Here are some basic facts about the immune system and virus transmission:

1. Not being exposed to a virus does not “weaken” your immune system.

2. If you are immunocompromised you are more likely to become sick when exposed to a pathogen.

3. If you are immunocompromised and become sick, your course of disease is more likely to be severe and more likely to be medically attended (a doctor visit, urgent care visit or hospitalization).

4. If you are immunocompromised you are likely to have higher virus load because viruses can replicate more easily in hosts with damaged immune systems.

5. Higher viral loads increase in the ability to transmit the virus to others.

6. If a population is generally suffering from a high rate of people being immunocompromised more people will become sick when a virus is in circulation. (For example, viral infections spread rapidly in nursing homes because as we age our immune system function declines).

An initial proposal made by some scientists re: “Immunity Debt” has required follow-up communications clarifying and insisting that their proposal only indicated timing of infection surge to be related to mask wearing and social distancing.

“We never affirmed that NPIs (non pharmaceutical interventions) would weaken the immune capacities of individuals or that lack of exposure to pathogens such as respiratory syncytial virus (RSV) and influenza could irrevocably damage the immune system.” Cohen, R. et al. Infect Disease Now. March, 2023

Despite this clarification anti-mask and anti-vaccine groups as well as perhaps well-meaning physicians have continued to use and mis-use the concept of ‘Immunity Debt’. And unfortunately, even the above description is easily rendered incorrect based on real world health data.

Public health data from the country of Sweden (below) and the fact that many places came out of “lockdown” at different times renders the Immunity Debt hypothesis null in the face of significant population based real-world data.

Arguments supporting “Immunity Debt” are based on the “handwaving” concept that priming your immune system with constant exposure to pathogens maintains some level of immunity. For this to be true chronic pathogen exposure would have to demonstrate the ability for the immune system to maintain antibody levels and some level of activity.

However, it is well known that antibody levels remain high post respiratory virus exposure for a short period of time where reinfection from some viruses can be prevented but then wane.

“Even when the production of RSV neutralizing antibody following RSV infection is robust, humoral immunity wanes over time. Reinfection during subsequent seasons is common.” Domachowske, J.B. and Rosenberg, H. F. Clinical Microbiology Reviews April, 1999

In addition, “Immunity Debt” does not explain the respiratory illness in adults who have memory immune cells that can last for decades. A few years of non-exposure to a pathogen does not diminish their efficacy.

The other argument I have come across is the belief that some level of chronic low-level pathogen exposure keeps our immune systems primed constantly. If this were true, antibodies would not naturally wane post respiratory virus illness. This argument uses the same logic as homeopathy which has indisputably failed every scientific test and clinical trail.

Finally, for pathogens such as RSV it is known that first time infections are typically less severe the older the child, the exact opposite of what “Immunity Debt” attempts to argue.

Population based data soundly refutes “Immunity Debt” causing more severe illness.

Let’s start by examining Sweden’s trippledemic. The country took a wildly different approach to masking and COVID lockdowns than much of the world and have suffered higher infection and death rates than their neighboring countries Finland, Denmark, and Norway. Leaders in Sweden admitted that their unique approach failed.

The unique approach did not include lockdowns. Many children in Sweden continued to go to daycares and schools. The University of Gothenburg, Sweden clearly states that primary schools were not closed. It has been reported that some children were sent home but were back to hybrid and in person studies in early 2021, well before the 2022-23 cold and flu season. But in general:

“Sweden's approach to the coronavirus pandemic is out of step with much of the world. The government never ordered a "shutdown" and kept day care centers and primary schools open.” Gretchen Vogel, Science, October 2020

Therefore children and adults would have experienced continued pathogen exposure. However, the 2022-23 respiratory virus season in Sweden was severe demonstrating that continued exposure to standard pathogens was not and is not protective.

Briefly, here are Influenza figures from the Swedish Government for 2022-23 season:

Here are RSV infection figures from the Swedish Government for the 2022-23 season:

*I apologize that they are in Swedish, I was unable to find an English translation for their published PDF on RSV.

Across Europe first reported RSV infections are starting months earlier than they did before the pandemic both last cold and flu season, and this 2023-24 cold and flu season as well. The 10 week shift between 2021/22 and 2022/23 could support the timing hypothesis which was the original purpose of developing the term “Immunity Debt” but it does not support severity. Furthermore, the striking difference in percent positivity between 2022/23 and 2023/24 indicates that many cases were missed in the 2022/23 surveillance and that the season likely started much earlier.

Another striking real-world example of post-COVID-19 immune system dysfunction can be found in the uptick of the rare mucormycosis or “black mold” infections around the world and the United States.

“10 reported COVID-19–associated mucormycosis cases occurred during a 79-day period (July 12–September 28, 2021) coinciding with a statewide surge in COVID-19 cases caused by the highly transmissible SARS-CoV-2 B.1.617.2 (Delta) variant.”

“Because of the severity of mucormycosis, it is important that clinicians maintain a high index of suspicion for COVID-19–associated mucormycosis, including in patients without severe immunocompromising conditions.” MMWR Dulski, T. M. et al. December 2021

Mucormycosis can have horrific physical consequences, often requiring significant amputations, cranial-facial surgeries, and removal of brain tissue just to ensure survival. A global surge of Mucormycosis cases occurred in 2021. The above excerpt is referring to an outbreak in Arkansas where 6 of the 10 infected died. None of them were vaccinated for COVID-19. One of the patients that died was an organ transplant recipient and immunocompromised, all had recently had COVID-19. Mucormycosis is considered very rare and typically only found in immunocompromised people such as those with active AIDS.

How Does COVID-19 Impact the Immune System?

There are hundreds of peer reviewed publications showing how COVID-19 damages the immune system. You can find select references (50 or so) under the header COVID: Immune System Dysfunction (LIL’ Science Linktree).

To summarize the studies here some of the impacts COVID can have on the immune system:

• Reduced T cell counts

• Higher numbers of T cells with exhaustion markers

• Reduction in the cells that produce interferon gamma and reduced Interferon gamma levels. (Interferon gamma is critical chemical messenger in the immune system for fighting off viruses.)

• COVID-19 may induce development of anti-cytokine antibodies

• Autoreactive B cells may develop post COVID-19

• Changes in innate immune responses that disrupt initial pathogen responses

This continued surge in respiratory viruses may be a harbinger of further illness.

The immune system doesn’t just fight pathogens. Our immune systems are also responsible for identifying and eliminating cancer cells. Immunocompromised people and people taking broadly immunosuppressive drugs have significantly higher rates of cancer. Cancer takes longer to develop than a respiratory virus infection, but I would not be surprised to see rates of cancer across all age groups increase significantly in the coming years.

Immune system suppression allows the reactivation of latent viruses such as Herpes Zoster the cause of Shingles and Epstein Barr virus. Epstein Barr virus was recently linked to the development of Multiple Sclerosis and it has long been linked to B cell lymphoma. Shingles may also be linked to development of dementia. Reactivation of both of these virus has been linked to COVID-19:

“A 2022 retrospective study compared 394,677 people over the age of 50 years who had contracted COVID-19 with those who had not yet had COVID-19. The study found that a COVID-19 diagnosis in people over 50 years old was associated with a significantly increased risk of developing shingles.” - Medical News Today

“Recent studies have observed Epstein-Barr virus (EBV) reactivation in patients with severe illness or long COVID, which may contribute to associated symptoms.” Bernal, K.D.E. and Whitehurst, C.B., September, 2023 Virus Research

Our immune systems live in a fine-tuned balance, dysregulation of which can also lead to autoimmune disease issues. Indeed more “self-antigen” directed antibodies are seen in human sera post virus infection, but COVID-19 leads to higher levels than what is seen with influenza. Auto-antibodies (self-directed antibodies) do not always mean autoimmune disease will develop, but they are an early signal.

However, a recent retrospective cohort study with over 3.8 million participants found significantly higher rates of the following autoimmune diseases post-SARS-CoV-2 infection:

• Rheumatoid arthritis

• Ankylosing spondylitis

• Systemic lupus erythematosus

• Dermatopolymyositis

• Systemic sclerosis

• Sjögren's syndrome

• Mixed connective tissue disease

• Behçet's disease

• Polymyalgia rheumatica

• Vasculitis

• Psoriasis

• Inflammatory bowel disease

• Celiac disease

• Type 1 diabetes

To summarize, the concept of “Immunity Debt” is irresponsible it that it may falsely indicate that these new illnesses dynamics are temporary. It is possibly providing false hope that people can somehow play ‘catch-up’ with viral exposures while returning to “normal life”.

Scientists and physicians raised the issue that “Immunity Debt” is a fabricated term not backed by any data this time last year. Many of us worked hard to remind people that repeat virus exposure and infection can be detrimental to your health.

We do not yet know how long COVID-19 induced immune system dysfunction lasts. We do know that some people recover over time while others still show evidence of immunosuppression over a year later. We also do not know exactly how much vaccination reduces COVID-19 induced immune system dysfunction. Often the more severe a COVID-19 infection the more likely long-term immune system issues will develop. Therefore, I would expect vaccination to be correlated with improved immune system function post COVID-19.

Continued promotion of the “Immunity Debt” conspiracy theory turned popular pseudoscience is playing a dangerous game that sacrifices our health and the health of our children.