IgG4 refers to a special rare subclass of antibodies instructing our immune system to ignore a pathogen rather than fight it. We learned that repeat Covid vaccinations cause immune tolerance in boosted people, which makes them less able to fend off repeat infections.
While IgG4 antibodies may naturally appear in allergies due to repeat immune stimulations with allergens, they are inappropriate for replicating pathogens such as SARS-CoV-2.
What causes such dysfunctional antibodies to appear in Covid-boosted people? Was the IgG4 class switch mechanistically caused by repeat injections or by the nature of mRNA technology? In August of 2023, I suggested that the culprit may be continued production of spike protein encoded by the mRNA Covid vaccines.
An interesting new preprint study confirms that suggestion. It compared the immune outcomes of three injections with mRNA vaccines against the effects of three injections of a protein-based vaccine called Novavax.