Vaccine-Induced IgG4 Increase: Another Example of Adaptive Immune Refocusing Following Breakthrough Infection

The elevated IgG4 levels in vaccinated individuals remain a popular topic, but the interpretation of this immunological response still leaves much to be desired. That is why I am summarizing below my reaction on X from a few weeks ago.

Increased IgG4 production is a consequence of immune refocusing. This phenomenon leads to enhanced recognition of more conserved spike(S)-associated antigenic domains, some of which exhibit amino acid homology with self-epitopes. The immune system, in its sophistication, attenuates the functional activity of antibodies (Abs), and subsequently also of T cells, generated through immune refocusing to minimize the risk of autoimmune responses. Of course, with repeated vaccine breakthrough infections (VBTIs), the risk of autoimmunity increases, as more conserved, self-like B cell and T cell epitopes are increasingly targeted over time. This nuanced immunological adaptation is too often erroneously interpreted as evidence of tolerogenic responses induced by COVID-19 (C-19) vaccination. However, these responses are unrelated to central or peripheral tolerance. Rather, they involve the production of an immunoglobulin isotype (IgG4) or Tc clones that have reduced affinity for conserved spike (S)-associated antigenic domains and, consequently, diminished functional capacity to neutralize the infectious virus or eliminate virus-infected cells, respectively.

The emergence of IgG4 Abs, for example, occurs indirectly due to high titers of previously induced Abs—primarily IgG1—which, for lack of functional binding to immunodominant S domains, mask these domains. This insufficient binding leads to reduced neutralizing capacity of these Abs and may arise either from epitope alterations in newly circulating variants or from the inherently low affinity of vaccine-induced Abs, particularly following repeated mRNA-based vaccination. The masking of immunodominant domains impairs their recognition and contributes to immune refocusing, thereby first promoting the generation of IgG4 Abs with diminished antiviral functionality. Such low-affinity IgG4 Abs may also be induced to certain allergens to dampen the immune response towards these allergens upon natural exposure, as has been extensively documented in the literature.

In my book (“The Inescapable Immune Escape Pandemic”), I explain that immune refocusing—and, therefore, the associated induction of suboptimal IgG4 Abs—can be triggered directly by repeated administration of mRNA-based C-19 vaccines, or indirectly by non-mRNA C-19 vaccines, once high titers of neutralizing Abs have been generated. The latter may no longer strongly bind to mutated immunodominant regions of the S protein in newly circulating SARS-CoV-2 (SC-2) variants when these variants cause VBTIs, thereby causing immune refocusing.

The bottom line is that vaccine efficacy declined with an increasing number of injections, not due to allegedly tolerogenic IgG4 Abs, but as an overall consequence of ongoing refocusing of adaptive immune responses—induced through repeated VBTIs with immune escape variants and/or repeated injections of mRNA-based C-19 vaccines.

This immunological explanation is quite different from what you read in the literature or hear from so-called experts. When one truly understands the immunological dynamics triggered by mRNA-based vaccines and/or VBTIs, it becomes clear that the generation of IgG4 Abs is merely a single ‘symptom’ in the cascade of adaptive immune dysregulatory events resulting from the dangerous immune refocusing induced by mRNA-based vaccines and/or VBTIs — both of which are tightly associated with the C-19 mass vaccination program.

However -as I have repeatedly pointed out recently- the virus is now no longer concentrating on derailing the adaptive immune response towards the circulating SC-2 variants, but focusing primarily on the dysregulation of the innate immune system. In many C-19 vaccinated individuals, the humoral arm of the innate immune system, together with a range of adaptive auxiliary immune mechanisms, played a crucial role in compensating for the lack of cell-mediated innate immunity and optimally functional Abs. A breakdown of the humoral innate immune system will ultimately lead to the virus itself effectively neutralizing immunity against this virus — and possibly against other viruses as well. This evolution is unfolding slowly but surely. Once it has fully taken place, all bets are off, and we must expect a storm of viral virulence to sweep through highly vaccinated populations.