Improvement of humoral immunity by repeated dose-intensified COVID-19 vaccinations in primary non- to low-responders and B cell deficient rheumatic disease patients.

OBJECTIVE: To determine whether repeated, dose-intensified mRNA vaccinations against COVID-19 increase humoral immunity in previously low-responding patients with autoimmune rheumatic diseases (AIRD), including rituximab-treated and B cell depleted patients. METHODS: Of 308 AIRD patients receiving basic immunization, 98 had a low serological response against SARS-CoV-2 with a neutralizing capacity of < 70% using surrogate neutralization assay. 38 patients received a third vaccination with 30 µg BNT162b2 16 weeks after second vaccination. If neutralizing serum capacity was below 70% four weeks after the last vaccination, then the fourth vaccination (n = 19) and the fifth (n = 4) vaccination with 100 µg mRNA-1273 took place eight weeks after the last vaccination. RESULTS: Each of the three booster vaccinations resulted in a significant increase of mean serum neutralizing capacity (3rd: Δ = 42%, p < 0.001; 4th: Δ = 19%, p = 0.049 and 5th: Δ = 51%, p = 0.043) and produced a significant proportion of high-responders (3rd: 34%; 4th: 32% and 5th: 75%). Low B cell counts (p = 0.047), lower previous antibody response (p < 0.001) and rituximab therapy (p = 0.021) were negatively associated with successful response to the third but not to the fourth vaccination. Remarkably, substantial increases in neutralization capacity of up to 99% were observed after repeated vaccinations in B cell depleted patients. CONCLUSION: AIRD patients with low humoral response benefited from up to three repeated dose-intensified mRNA booster vaccinations - despite low B cell count and previous rituximab therapy. Each additional vaccination substantially reduced the number of low-responding, vulnerable patients.

Type of vaccine and immunosuppressive therapy but not diagnosis critically influence antibody response after COVID-19 vaccination in patients with rheumatic disease

Objective The development of sufficient COVID-19 vaccines has been a big breakthrough in fighting the global SARS-CoV-2 pandemic. However, vaccination effectiveness can be reduced in patients with autoimmune rheumatic diseases (AIRD). The aim of this study was to identify factors that lead to a diminished humoral vaccination response in patients with AIRD. Methods Vaccination response was measured with a surrogate virus neutralisation test and by testing for antibodies directed against the receptor-binding-domain (RBD) of SARS-CoV-2 in 308 fully vaccinated patients with AIRD. In addition, 296 immunocompetent participants were investigated as a control group. Statistical adjusted analysis included covariates with a possible influence on antibody response. Results Patients with AIRD showed lower antibody responses compared with immunocompetent individuals (median neutralising capacity 90.8% vs 96.5%, p<0.001;median anti-RBD-IgG 5.6 S/CO vs 6.7 S/CO, p<0.001). Lower antibody response was significantly influenced by type of immunosuppressive therapy, but not by rheumatic diagnosis, with patients under rituximab therapy developing the lowest antibody levels. Patients receiving mycophenolate, methotrexate or janus kinase inhibitors also showed reduced vaccination responses. Additional negative influencing factors were vaccination with AZD1222, old age and shorter intervals between the first two vaccinations. Conclusion Certain immunosuppressive therapies are associated with lower antibody responses after vaccination. Additional factors such as vaccine type, age and vaccination interval should be taken into account. We recommend antibody testing in at-risk patients with AIRD and emphasise the importance of booster vaccinations in these patients.

Pausing methotrexate improves immunogenicity of COVID-19 vaccination in elderly patients with rheumatic diseases.

OBJECTIVE: To study the effect of methotrexate (MTX) and its discontinuation on the humoral immune response after COVID-19 vaccination in patients with autoimmune rheumatic diseases (AIRD). METHODS: In this retrospective study, neutralising SARS-CoV-2 antibodies were measured after second vaccination in 64 patients with AIRD on MTX therapy, 31 of whom temporarily paused medication without a fixed regimen. The control group consisted of 21 patients with AIRD without immunosuppressive medication. RESULTS: Patients on MTX showed a significantly lower mean antibody response compared with patients with AIRD without immunosuppressive therapy (71.8% vs 92.4%, p<0.001). For patients taking MTX, age correlated negatively with immune response (r=-0.49; p<0.001). All nine patients with antibody levels below the cut-off were older than 60 years. Patients who held MTX during at least one vaccination showed significantly higher mean neutralising antibody levels after second vaccination, compared with patients who continued MTX therapy during both vaccinations (83.1% vs 61.2%, p=0.001). This effect was particularly pronounced in patients older than 60 years (80.8% vs 51.9%, p=0.001). The impact of the time period after vaccination was greater than of the time before vaccination with the critical cut-off being 10 days. CONCLUSION: MTX reduces the immunogenicity of SARS-CoV-2 vaccination in an age-dependent manner. Our data further suggest that holding MTX for at least 10 days after vaccination significantly improves the antibody response in patients over 60 years of age.