• Health

COVID-19 vaccines don’t cause immunodeficiency and aren’t associated with excess mortality

Posted on:  2023-02-07

Key takeaway

Vaccines train the immune system to efficiently respond to one specific pathogen; they don’t prevent our immune system from combating other pathogens or cancer. COVID-19 vaccines are effective at protecting against death and severe COVID-19 and aren’t responsible for the excess mortality observed in 2022.

Reviewed content


“most of the individuals who had been fully vaccinated would develop full-blown vaccine-induced acquired immunodeficiency syndrome by the end of the month”

Source: The Exposé, Anonymous, 2022-01-22

Verdict detail

Incorrect: Vaccines induce a pathogen-specific immunological memory. The ability of a vaccine to stimulate immunological memory against one pathogen doesn’t tell us about the immune system’s ability to combat other pathogens or diseases. Hence, the alleged lack of effectiveness of COVID-19 vaccines wouldn’t mean that the immune system cannot fight back other infections or cancer.
Factually inaccurate: The Exposé used erroneous data to calculate COVID-19 vaccine effectiveness. These erroneous data underestimate the number of COVID-19 cases among unvaccinated people by a factor of five.

Full Claim

“most of the individuals who had been fully vaccinated would develop full-blown vaccine-induced acquired immunodeficiency syndrome by the end of the month”; “the average German was down to the last 12.3% of his or her immune system for fighting certain classes of viruses and certain cancers”


Inaccurate claims that COVID-19 vaccines weaken the immune system instead of boosting our immune defenses against SARS-CoV-2 have repeatedly surfaced on the internet. Health Feedback reviewed several of them and found them to be baseless, commonly involving flawed data interpretation or a misunderstanding of biology.

Another such example is an article on The Exposé, later republished on NewsPunch, a website with a track record of publishing misinformation. The article claimed that “most of the individuals who had been fully vaccinated would develop full-blown vaccine-induced acquired immunodeficiency syndrome by the end of the month”.

To support its claim, the article cited COVID-19 epidemiological data from a 31 December 2021 report by the Robert Koch Institute (RKI) in Germany and concluded that “the immune systems of the fully vaccinated had already degraded to an average of minus 87%”, meaning that “the average German was down to the last 12.3% of his or her immune system for fighting certain classes of viruses and certain cancers”.

However this claim is inaccurate. It uses erroneous data and demonstrates a fundamental lack of understanding of immunology, as we will show below.

The article used an inaccurate figure for COVID-19 cases in unvaccinated people, fails to account for caveats in RKI data

First, the article used erroneous data to claim that “the vaccinated were […] 8.12x more likely to be infected with Omicron than the unvaccinated in Germany”. According to the Exposé, a 31 December 2021 RKI report showed that, in a sample of 6,788 COVID-19 cases for which symptom information was available, 186 were from unvaccinated people and 4,020 were from fully vaccinated people.

However, the report was later corrected, as the text in red on the first page of their report indicates. Specifically, the number of cases among unvaccinated people was corrected from 186 to 1,097. This correction was made on 3 January 2022, almost three weeks before the publication of the Exposé and NewsPunch articles on 22 January 2022. Therefore, the number of cases among unvaccinated individuals was actually five-fold higher than what the Exposé claimed.

But even if The Exposé used the corrected data, their calculation still wouldn’t be correct. To compare the proportion of unvaccinated and vaccinated people among COVID-19 cases, it is important to consider the proportion of vaccinated and unvaccinated people in the population. If there are many more vaccinated people in the population, it is expected that there will be more vaccinated people among COVID-19 cases, because vaccines aren’t 100% effective. And at the time of the report’s publication, more than 70% of Germany’s population was fully vaccinated.

In order to calculate the incidence of COVID-19 in vaccinated and unvaccinated groups, The Exposé used the ratio of the number of cases in vaccinated (or unvaccinated) people to the percentage of people in Germany with the respective vaccination status, writing: “the unvaccinated had 186 cases out of 26.5% of the population […] the fully vaccinated had 4020 cases out of 70.53% of the population. So the vaccinated Omicron case incidence was 57 per 1 per cent of the population […] the unvaccinated Omicron case incidence was just 7.02 per 1 per cent of the population”.

But this calculation relies on the assumption that the characteristics of these 6,788 cases closely reflect the characteristics of the general population, even though there isn’t enough information to reliably assume this is true.

In order to calculate the risk of infection, we need to have additional information about these 6,788 COVID-19 cases apart from their vaccination status, such as the ages of these individuals. This is important information because the proportion of vaccinated and unvaccinated people can differ significantly depending on the age group. For example, 90% of the population above 60 was vaccinated as of February 2023, but vaccine coverage in those aged 12 to 17 was 70%.

Therefore, the risk will change depending on whether we are dealing with a predominantly teenage population with a lower vaccine coverage (a smaller vaccinated group), or the elderly with a higher vaccine coverage (a larger vaccinated group). Failing to account for inherent differences in population size results in the base rate fallacy. The additional information required for the calculation isn’t available, rendering the mathematical demonstration by The Exposé moot.

Vaccine effectiveness doesn’t measure the immune system’s strength

The Exposé then used their flawed vaccine effectiveness calculation to claim that vaccinated people develop vaccine-induced AIDS (acquired immunodeficiency syndrome). AIDS is an infectious disease caused by the human immunodeficiency virus (HIV) and completely unrelated to COVID-19 or COVID-19 vaccines. This claim hinges on the false notion that vaccine effectiveness is a measure of the strength of the immune system, with a low or negative vaccine effectiveness denoting the failure of the immune system. However, this is incorrect.

Vaccination relies on mimicking a real infection to stimulate formation of immunological memory against this infection. In that respect, it is true that a high and long-lasting vaccine effectiveness means that the immune system effectively responded to the vaccination and developed immunological memory.

But the author veered into inaccuracy by claiming “this means that the average German was down to the last 12.3% of his or her immune system for fighting certain classes of viruses and certain cancers”.

This is because vaccine-induced immunological memory involves cellular and molecular components—mostly memory T cells, B cells and circulating antibodies—that are specific to the infectious agent[1,2]. A COVID-19 vaccine stimulates the development of memory T cells, B cells and circulating antibodies specific to SARS-CoV-2, while the flu vaccine stimulates the development of memory cells and circulating antibodies specific to the influenza virus, and so on. Vaccine effectiveness affects the immune system’s ability to combat the pathogen targeted by the vaccine, but isn’t otherwise a reflection of the immune system’s ability to combat other threats. The level of COVID-19 vaccine effectiveness doesn’t tell us how well vaccinated people fight other infectious diseases or cancer.

Moreover, there’s no evidence supporting the claim that vaccinated people are now immunodeficient. If this were true, then we would expect to see cases of infectious diseases skyrocket only in vaccinated people but not unvaccinated people, which isn’t happening.

Germany’s excess mortality in 2022 isn’t a sign that vaccinated people are immunodeficient

The Exposé then presented the excess mortality in Germany in 2022 as proof that “something is not right and that the true impact of the Covid-19 injections needs to be fully understood”.

Excess mortality is determined by comparing how many people were expected to have died based on the previous years’ mortality with how many people actually died. Many countries experienced some level of excess mortality throughout 2022. In particular, Germany experienced 102,500 excess deaths in 2022, according to data from the Organization for Economic Co-operation and Development to date.

However, the Exposé didn’t produce any evidence that COVID-19 vaccination is causally associated with all-cause mortality. In fact, this is a recurring claim that Health Feedback addressed on several occasions.

Many factors are likely to contribute to excess mortality, such as heat waves during the summer, indirect consequences of COVID-19 infection, or the strain on healthcare systems during the pandemic, as Health Feedback explained.

More importantly, studies show that vaccinated people aren’t dying in higher proportions than unvaccinated people. One study looked at excess mortality in the U.S. and other peer countries between June 2021 and March 2022. It reported that excess all-cause mortality was greater in the ten least-vaccinated states than in the ten most-vaccinated states[3].

A CDC study examining the period between December 2020 and July 2021 found vaccinated people had lower non-COVID-19 mortality risks than unvaccinated individuals[4]. Another study in over more than 520,000 people reached a similar conclusion: the all-cause mortality was 37% lower in the vaccinated group[5].


The Exposé incorrectly claimed that COVID-19 vaccines caused immunodeficiency, based on a flawed calculation of vaccine effectiveness that used inaccurate information and didn’t account for caveats associated with the data, such as the lack of information about the vaccination status of COVID-19 cases in the report.

In addition, this claim ignored the fact that a vaccine-induced immune response is specific to the infectious agent targeted by the vaccine and has no bearing on the immune response to other threats.

This claim is part of a wider narrative incorrectly associating COVID-19 vaccines with an increased risk of death. But as Health Feedback explained in previous publications, there is no evidence associating COVID-19 to immunodeficiency or excess mortality as a whole.


Science Feedback is a non-partisan, non-profit organization dedicated to science education. Our reviews are crowdsourced directly from a community of scientists with relevant expertise. We strive to explain whether and why information is or is not consistent with the science and to help readers know which news to trust.
Please get in touch if you have any comment or think there is an important claim or article that would need to be reviewed.

Published on:

Related Articles