The following is a summary of “Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine response in adults with predominantly antibody deficiency,” published in the May 2024 issue of Allergy & Immunology by Zhang, et al.

Individuals with predominantly antibody deficiency (PAD) tend to exhibit lower anti–severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike antibody levels following the initial 2-dose SARS-CoV-2 vaccination compared to healthy individuals. The antibody responses and neutralization capabilities in patients with PAD after subsequent vaccine doses are not well understood. For a study, researchers sought to assess anti-spike antibody responses in adults with PAD over five SARS-CoV-2 vaccine doses and identify diagnostic and immunophenotypic risk factors associated with diminished antibody responses.

The study evaluated anti-spike antibody levels in 117 patients with PAD and 192 healthy adult controls after up to five SARS-CoV-2 immunizations. It measured the neutralization of both the SARS-CoV-2 wild-type strain and the Omicron BA.5 variant and analyzed infection outcomes.

Patients with PAD had significantly lower average anti-spike antibody levels after three SARS-CoV-2 vaccine doses compared to healthy controls (1,439.1 vs 21,890.4 U/mL [P < .0001]). Those with secondary PAD, severe primary PAD, and high-risk immunophenotypes showed reduced mean anti-spike antibody levels after doses 2, 3, and/or 4, but not after the fifth dose. Compared to patients with mild and moderate PAD, those with severe PAD exhibited a steeper increase in anti-spike antibody levels across the five doses. A strong positive correlation was found between anti-spike antibody levels and neutralization capacity for both the SARS-CoV-2 wild-type strain and the Omicron BA.5 variant. Most infections were managed on an outpatient basis.

Successive SARS-CoV-2 immunizations in patients with PAD led to increased anti-spike antibody levels, correlated with neutralization of both the SARS-CoV-2 wild-type strain and the Omicron BA.5 variant. Lower mean anti-spike antibody levels after doses 2 through 4 were associated with secondary PAD, severe primary PAD, and high-risk immunophenotypes. Patients with severe PAD had the highest rate of increase in anti-spike antibody levels over five immunizations, suggesting a significant benefit of continued SARS-CoV-2 vaccinations, particularly for high-risk patients with PAD.

Reference: jaci-global.org/article/S2772-8293(24)00030-4/fulltext