Immune Exhaustion Emerges After 3rd Vaccine Dose: Current Findings

Finding suggests how little we know about the immune system

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Vaccines have been upheld as the best strategy for dealing with infectious diseases, but that’s largely because of a limited understanding of the immune system and how to best complement and support its function. Our bodies are normally able to separate the wheat from the chaff when it comes to invading pathogens or when a vaccine stimulates an immune reaction, but there are factors that can compromise that.

A study published in Science Immunology in January 2023 (but first submitted in August 2022) shows that incremental doses of the mRNA COVID-19 vaccine boosters may be one such factor, based on how they train our immune systems. In this case, the immune system seemed to gain a false sense of security from dealing with the booster version of the vaccine, which is supposed to teach the immune system how to deal with the virus. Unfortunately, in this case, it seemed that the immune system has learned that it doesn’t need to mount a strong counterattack. Worse, the vaccine boosters might not even induce any effect in people at high risk of severe infection.

IgG Subtype Composition Changed After Vaccination

According to the study, the third dose of the mRNA vaccines seems to be linked with a class switch in subtypes of immunoglobulin G (IgG), the dominating serum antibody in our immune system, which raises the question of immune exhaustion. Class switching is when B cells redirect their efforts toward producing IgG. To start, they produce generic immunoglobulin cells such as IgM. But once they find that the invading pathogen is tougher than they thought, they switch to producing the more effective IgG to ward off the infection.