medwireNews: SARS-CoV-2 vaccination “essentially works” in people with immune-mediated inflammatory diseases (IMIDs), but humoral immune responses may be delayed and reduced, researchers report.
These findings are based on an analysis of 84 patients with IMIDs – including spondyloarthritis (32.1%), rheumatoid arthritis (29.8%), systemic rheumatic diseases (19.1%), inflammatory bowel disease (9.5%), and psoriasis (9.5%) – and 182 healthy controls. All participants had been given at least one dose of the Pfizer–BioNTech (BNT162b2) vaccine at least 10 days previously, with the majority (96.0%) having received both doses, and all patients had tested negative for SARS-CoV-2 antibodies prior to their first dose.
All healthy controls developed antibodies to the S1 domain of the spike protein of SARS-CoV-2 and were categorized as responders, but five (6%) patients with IMIDs did not respond to vaccination, with lack of immunogenicity at 11, 27, and 39 days after the second dose in three of these individuals. Antibody positivity was defined as an optical density (OD) of 0.8 units or more when determined at 450 nm using a commercial ELISA assy.
Georg Schett (Friedrich-Alexander University Erlangen-Nuremberg, Germany) and team then measured the development of neutralizing antibodies using an assay measuring the ability of anti-SARS-CoV-2 antibodies to block the binding of the SARS-CoV-2 receptor-binding domain to ACE2. They found that a significantly smaller proportion of IMID patients versus controls developed neutralizing antibodies, at 90.5% versus 99.5%.
“Thus, roughly 1 out of 10 patients with IMID fails to develop neutralising antibodies after SARS-CoV-2 vaccination, while it is only 1 out of 100 in the controls,” write the study authors, noting that their findings contrast with data from a small study suggesting that all patients with rheumatic diseases have a response.
They also report in the Annals of the Rheumatic Diseases that antibody responses were delayed in people with IMIDs relative to controls. Analysis of immunogenicity over time illustrated that there was a “relatively large” difference in OD measurements between the two groups in the days following the second vaccination, but this difference “converged over time.”
Moreover, a linear model of group–time interactions showed that the adjusted mean difference in OD between people with IMIDs and controls was a significant 2.21 units at day 28 after the first vaccine dose, decreasing to a nonsignificant 0.07 units at day 70.
“Delayed antibody responses to the SARS-CoV-2 vaccine may suggest an effect of immune-modulatory treatments,” suggest Schett and team. However, they say that “we could not objectify this hypothesis,” because untreated patients with IMIDs (n=24) also had lower antibody responses than healthy controls, and there were “no differences” in antibody responses among those treated with conventional DMARDs (n=20) versus biologics or JAK inhibitors (n=36).
The researchers conclude that although efficacy was “somewhat delayed and reduced” in their study, “the data also show that, in principle, patients with IMID respond to SARS-CoV-2 vaccination, supporting an aggressive vaccination strategy.”
medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2021 Springer Healthcare Ltd, part of the Springer Nature Group
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