A paper in Vaccines: IgG4 Antibodies Induced by Repeated Vaccination May Generate Immune Tolerance to the SARS-CoV-2 Spike Protein examines the possibility that repeated doses of the mRNA vaccine administered to prevent COVID 19 infection may cause autoimmune disease in susceptible patients. The abstract is below. I have underlined a key part of it.

Less than a year after the global emergence of the coronavirus SARS-CoV-2, a novel vaccine platform based on mRNA technology was introduced to the market. Globally, around 13.38 billion COVID-19 vaccine doses of diverse platforms have been administered. To date, 72.3% of the total population has been injected at least once with a COVID-19 vaccine. As the immunity provided by these vaccines rapidly wanes, their ability to prevent hospitalization and severe disease in individuals with comorbidities has recently been questioned, and increasing evidence has shown that, as with many other vaccines, they do not produce sterilizing immunity, allowing people to suffer frequent re-infections. Additionally, recent investigations have found abnormally high levels of IgG4 in people who were administered two or more injections of the mRNA vaccines. HIV, Malaria, and Pertussis vaccines have also been reported to induce higher-than-normal IgG4 synthesis. Overall, there are three critical factors determining the class switch to IgG4 antibodies: excessive antigen concentration, repeated vaccination, and the type of vaccine used. It has been suggested that an increase in IgG4 levels could have a protecting role by preventing immune over-activation, similar to that occurring during successful allergen-specific immunotherapy by inhibiting IgE-induced effects. However, emerging evidence suggests that the reported increase in IgG4 levels detected after repeated vaccination with the mRNA vaccines may not be a protective mechanism; rather, it constitutes an immune tolerance mechanism to the spike protein that could promote unopposed SARS-CoV2 infection and replication by suppressing natural antiviral responses. Increased IgG4 synthesis due to repeated mRNA vaccination with high antigen concentrations may also cause autoimmune diseases, and promote cancer growth and autoimmune myocarditis in susceptible individuals.

The authors of the paper offer an interesting and important hypothesis, but it is still uncertain. The mRNA vaccine given to billions of people were done so after a very short time following their development and administered under emergency authorization. This period was so brief that long-term or even intermediate adverse events would not have been observed. Not only was the test period limited, but the mRNA technique is also relatively new. Thus, it would not be surprising if unwanted side effects occurred after widespread use.

Disease protection from these vaccines is limited and repeated doses have been given. Initially, deaths from COVID were higher in the unvaccinated than in the vaccinated. Subsequently, however, the situation reversed. Deaths were higher in the vaccinated who received a third dose than in the unvaccinated. The authors of the study suggest that overproduction of IgG, secondary to repeated vaccine administration, may cause harm by inducing a variety of harmful antibody mediated diseases. They further propose that repeated injections of the vaccine may actually weaken the protective effects of the vaccine.

They also suggest that the six unwanted effects below may be caused, at least in part, by repeated doses of the vaccine. This is just one report, but the later discovery of important adverse effects of many treatments initially thought safe and/or effective is a common event. Clinicians need to be vigilant and report all possible adverse effects following vaccination. Such vigilance is necessary to evaluate the effectiveness of the therapeutic pool we dove into without knowing the depth of the water. The reluctance of the both the government and the medical profession to allow free discussion of the therapeutic profile of these vaccines is a stain on both.

(1) By ignoring the spike protein synthesized as a consequence of vaccination, the host immune system may become vulnerable to re-infection with the new Omicron subvariants, allowing for free replication of the virus once a re-infection takes place. In this situation, we suggest that even these less pathogenic Omicron subvariants could cause significant harm and even death in individuals with comorbidities and immuno-compromised conditions.

(2) mRNA and inactivated vaccines temporally impair interferon signaling possibly causing immune suppression and leaving the individual in a vulnerable situation against any other pathogen. In addition, this immune suppression could allow the re-activation of latent viral, bacterial, or fungal infections and might also allow the uncontrolled growth of cancer cells.

3) A tolerant immune system might allow SARS-CoV-2 persistence in the host and promote the establishment of a chronic infection, similar to that generated by the hepatitis B virus, the human immune deficiency virus, and the hepatitis C virus.

(4) The combined immune suppression (produced by SARS-CoV-2 infection and further enhanced by vaccination) could explain a plethora of autoimmune conditions, such as cancers, re-infections, and deaths temporally associated with both. It is conceivable that the excess deaths reported in several highly COVID-19-vaccinated countries may be explained, in part, by this combined immunosuppressive effect.

(5) Repeated vaccination could also lead to autoimmunity.

(6) Increased IgG4 levels induced by repeated vaccination could lead to autoimmune myocarditis.