The vaccinations included 8 different vaccine formulations, including updated boosters.
As reported by Ars TechnicaA 62-year-old German resident received 217 COVID-19 vaccinations over 29 months — for «personal reasons», but did not experience any adverse effects from hyperimmunization.
This case is rather an exception to the rule, as researchers have repeatedly expressed concern about over-immunization, which can lead to a weakened immune response, among other things.
«In the case of chronic exposure to a disease-causing microorganism, there are signs that certain types of immune cells, known as T cells, «become fatigued» and release fewer pro-inflammatory mediators», — according to a study published in The Lancet Infectious Diseases.
Over-immunization can also cause what is known as «immune tolerance», which leads to weaker responses that are less effective in fighting the pathogen.
Meanwhile, the team of researchers contacted the over-vaccinated German, whose actions are currently being investigated for fraud, and invited him to undergo some tests: in particular, they took saliva and blood samples during his 214–217 vaccinations and compared the immune responses with those of 29 other people who received the standard 3 vaccinations. It turned out that although some aspects of his protection were stronger, his overall immune response was functionally similar to that of people who had received far fewer doses. The level of antibodies in his blood increased after the new dose, but then began to decline, similar to what was observed in the control group.
The ability of the subject’s antibodies to neutralize SARS-CoV-2 was 5–11 times higher than that of the control group — however, the researchers noted that this was due to the greater number of antibodies, not their greater potency. Specific subgroups of immune cells, namely B cells trained against the SARS-CoV-2 S-protein and effector T cells, were elevated compared to other people, but seemed to function normally.
As an additional type of control, the researchers also looked at the man’s immune response to Epstein-Barr virus, which causes mononucleosis, and found that unrestricted immunization did not negatively affect the response to this virus, suggesting no negative impact on immune responses in general. Numerous types of testing also showed that the man had never been infected with SARS-CoV-2, although the researchers noted that this could be due to other precautions the man had taken in addition to vaccination.
«In summary, our report shows that SARS-CoV-2 hypervaccination in this case did not lead to negative consequences and increased the number of adhesion-specific antibodies and T cells without having a strong positive or negative effect on the intrinsic quality of adaptive immune responses,» the authors concluded. «Importantly, we do not endorse hypervaccination as a strategy to enhance adaptive immunity».