T cell responses to SARS-CoV-2 vaccination in people with multiple sclerosis differ between disease-modifying therapies (preprint)

Immune responses in people with multiple sclerosis (pwMS) on disease-modifying therapies (DMTs) have been of significant interest throughout the COVID-19 pandemic. Lymphocyte-targeting immunotherapies including anti-CD20 treatments and sphingosine-1-phosphate receptor (S1PR) modulators attenuate antibody responses after vaccination. Evaluation of cellular responses after vaccination is therefore of particular importance in these populations. In this study, we analysed CD4 and CD8 T cell functional responses to SARS-CoV-2 spike peptides in healthy controls and pwMS on five different DMTs by flow cytometry. Although pwMS on anti-CD20 and S1PR therapies had low antibody responses after both 2 and 3 vaccine doses, T cell responses in pwMS on anti-CD20 therapies were preserved after third vaccination, even when additional anti-CD20 treatment was administered between vaccine doses 2 and 3. PwMS taking S1PR modulators had low detectable T cell responses in peripheral blood. CD4 and CD8 T cell responses to SARS-CoV-2 variants of concern Delta and Omicron were lower than to the ancestral Wuhan-Hu-1 variant. Our results indicate the importance of assessing both cellular and humoral responses after vaccination and suggest that even in the absence of robust antibody responses vaccination can generate immune responses in pwMS.

Titers of antibodies the receptor-binding domain (RBD) of ancestral SARS-CoV-2 are predictive for levels of neutralizing antibodies to multiple variants (preprint)

Diagnostic assays currently used to monitor the efficacy of COVID-19 vaccines measure levels of antibodies to the receptor-binding domain of ancestral SARS-CoV-2 (RBDwt). However, the predictive value for protection against new variants of concern (VOCs) has not been firmly established. Here, we used bead-based arrays and flow cytometry to measure binding of antibodies to spike proteins and receptor-binding domains (RBDs) from VOCs in 12,000 sera. Effects of sera on RBD-ACE2 interactions were measured as a proxy for neutralizing antibodies. The samples were obtained from healthy individuals or patients on immunosuppressive therapy who had received two to four doses of COVID-19 vaccines and from COVID-19 convalescents. The results show that anti-RBDwt titers correlate with the levels of binding- and neutralizing antibodies against the Alpha, Beta, Gamma, Delta, Epsilon and Omicron variants. The benefit of multiplexed analysis lies in the ability to measure a wide range of anti-RBD titers using a single dilution of serum for each assay. The reactivity patterns also yield an internal reference for neutralizing activity and binding antibody units per milliliter (BAU/ml). Results obtained with sera from vaccinated healthy individuals and patients confirmed and extended results from previous studies on time-dependent waning of antibody levels and effects of immunosuppressive agents. We conclude that anti-RBDwt titers correlate with levels of neutralizing antibodies against VOCs and propose that our method may be implemented to enhance the precision and throughput of immunomonitoring.

Multiplexed measurement of binding- and neutralizing antibodies to SARS-CoV-2 variants in 12.000 post-vaccine sera (preprint)

Diagnostic assays currently used to monitor the efficacy of COVID-19 vaccines measure levels of antibodies to the receptor-binding domain of ancestral SARS-CoV-2 (RBDwt). However, the predictive value for protection against new variants of concern (VOCs) has not been firmly established. Here, we used bead-based arrays and flow cytometry to measure binding of antibodies to spike proteins and receptor-binding domains (RBDs) from VOCs in 12,000 sera. Effects of sera on RBD-ACE2 interactions were measured as a proxy for neutralizing antibodies. The samples were obtained from healthy individuals or patients on immunosuppressive therapy who had received two to four doses of COVID-19 vaccines and from COVID-19 convalescents. The results show that anti-RBDwt titers correlate with the levels of binding- and neutralizing antibodies against the Alpha, Beta, Gamma, Delta, Epsilon and Omicron variants. The benefit of multiplexed analysis lies in the ability to measure a wide range of anti-RBD titers using a single dilution of serum for each assay. The reactivity patterns also yield an internal reference for neutralizing activity and binding antibody units per milliliter (BAU/ml). Results obtained with sera from vaccinated healthy individuals and patients confirmed and extended results from previous studies on time-dependent waning of antibody levels and effects of immunosuppressive agents. We conclude that anti-RBDwt titers correlate with levels of neutralizing antibodies against VOCs and propose that our method may be implemented to enhance the precision and throughput of immunomonitoring.

Efficacy and safety of a third SARS-CoV-2 vaccination in multiple sclerosis vaccine non-responders (preprint)

Importance: Vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to protect against coronavirus disease of 2019 (COVID-19) is recommended for patients with multiple sclerosis (pwMS). However, approximately 80% of all pwMS treated with anti-CD20 therapy (rituximab, ocrelizumab) or fingolimod have low or absent humoral immunity after vaccination with two doses of SARS-CoV-2 mRNA vaccines. The efficacy and safety of a third vaccine dose in this group is largely unknown. Objective: To characterize the humoral immunogenicity and the safety of a third dose of mRNA-COVID-19 vaccine in anti-CD20- or fingolimod-treated pwMS with low or absent humoral immunity (i.e., anti-SARS-CoV-2 IgG <70 arbitrary units (AU) and <5 AU, respectively) after two vaccinations. Design, setting and participants: 130 anti-CD20- or fingolimod-treated pwMS with low or absent humoral immunity despite full vaccination against SARS-CoV-2, received a third dose of SARS-CoV-2 mRNA vaccine. Humoral immunity (i.e., antibody response against SARS-CoV-2) and the frequency and characteristics of side-effects were analyzed in all participants. Exposures: A third vaccine dose against SARS-CoV-2 with BNT162b2- or mRNA-1273-COVID-19 vaccine. Main outcomes and measures: Patient- and treatment-specific variables were acquired using a digital questionnaire, the Norwegian Immunization Registry and hospital journals. Humoral immunity was assessed by measuring SARS-CoV-2 SPIKE receptor-binding domain (RBD) IgG response. Low/absent humoral immunity was assumed in cases of AU<70 after anti-SPIKE protein-based serology 3-5 weeks after revaccination. Results: A third dose of SARS-CoV-2 mRNA vaccine increased anti-SARS-CoV-2 SPIKE RBD IgG levels significantly. The proportion of patients with assumed protective humoral immunity (anti-SARS-CoV-2 SPIKE RBD IgG > 70 AU) were 25% among patients using anti-CD20 therapy and 7% among those treated with fingolimod. No adverse events were registered during the study period. Conclusion and relevance: A third dose of mRNA-COVID-19 vaccine was associated with significantly increased levels of anti-SARS-CoV-2 SPIKE RBD IgG, and hence assumed protective humoral immunity - in anti-CD20- or fingolimod-treated pwMS with low or absent humoral immunity despite full vaccination. The effect of a third vaccine dose was limited and more prominent among those treated with anti-CD20 therapy.