Boosting Immunity, Boosting Risk? The Surprising Link Between IgG4 and COVID Breakthrough Infections
Post-Vaccination IgG4 and IgG2 Class Switching is linked to Increased Risk of SARS-CoV-2 Infections A new study published in Infectious Disease Practice has revealed a concerning correlation between the class switching of antibodies after COVID-19 mRNA booster vaccinations and a heightened risk of breakthrough infections. Specifically, the study found that elevated levels of IgG4 and IgG2 antibodies, which increase significantly following the third mRNA dose, are linked to an increased risk of symptomatic SARS-CoV-2 infections. The study analyzed a longitudinal subset of 83 healthcare workers who received three doses of the COVID-19 vaccine. Additionally, they included 66 healthcare workers from the same cohorts who were analyzed at a specific timepoint (T9) corresponding to May 2022, four months after the first booster vaccination. The study, conducted by a team of researchers from Spain, tracked the immune responses of healthcare workers over nearly three years. They observed ...