The following is a summary of “Functionally impaired antibody response to BNT162b2 booster vaccination in CVID IgG responders,” published in the APRIL 2023 issue of Allergy & Immunology by Sauerwein, et al.

In patients with common variable immunodeficiency (CVID), previous studies have shown the production of IgG antibodies following mRNA vaccination with the BNT162b2 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine. However, the functionality of these antibodies in terms of avidity (measured by dissociation rate constant) and their response to booster immunization has yet to be thoroughly investigated. Therefore, for a study, researchers sought to analyze the avidity of anti-SARS-CoV-2 serum antibodies, their neutralization capacity, and the response of circulating follicular T-helper cells after a third vaccination with the BNT162b2 SARS-CoV-2 mRNA vaccine in CVID responders and healthy individuals.

The study analyzed binding IgG, IgA, and IgM serum levels using ELISA in CVID responders (n = 10) and healthy controls (n = 41) who responded to the primary vaccination. The binding avidity of anti-spike antibodies was measured using biolayer interferometry with the biotin-labeled receptor-binding domain of the SARS-CoV-2 spike protein and streptavidin-labeled sensors. Antigen-specific recall T-cell responses were assessed using activation-induced markers measured by flow cytometry.

After the third vaccination, CVID responders exhibited lower levels of IgG, IgM, and IgA antibodies, surrogate virus-neutralizing antibodies, and antibody avidity compared to healthy controls. However, following the primary vaccination, anti-SARS-CoV-2 spike protein avidity was comparable between CVID responders and healthy individuals. In addition, the follicular T-helper cell response to booster vaccination was significantly reduced in CVID responders compared to healthy individuals.

The impaired affinity maturation observed during the booster response provided new insights into the pathophysiology of CVID. The study highlights the differences in antibody responses and T-cell responses to vaccination in CVID patients, which may contribute to our understanding of CVID and inform future vaccine strategies in the population.

Source: jacionline.org/article/S0091-6749(22)01618-9/fulltext