key: cord-0299843-awum2fo6
authors: Konig, M.; Torgauten, H. M.; Overas, M. H.; Chopra, A.; Lorentzen, A. R.; Tran, T. T.; Mjaaland, S.; Aaberge, I. S.; Myhr, K.-M.; Wergeland, S.; Berge, T.; Harbo, H. F.; Torkildsen, O. F. G.; Holmoy, T.; Celius, E. G.; Munthe, L. A.; Vaage, J. T.; Lund-Johansen, F.; Nygaard, G. O.
title: Efficacy and safety of a third SARS-CoV-2 vaccination in multiple sclerosis vaccine non-responders
date: 2021-10-18
journal: nan
DOI: 10.1101/2021.10.15.21264977
sha: d83a10b4f88e1524cb4d30a10aa5a0e18ad92355
doc_id: 299843
cord_uid: awum2fo6

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.

Introduction: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) corona disease of 2019 (COVID-19) is associated with high mortality and detrimental effects on society, economy, and individual lives. Patients with multiple sclerosis (pwMS) do not have an increased risk of SARS-CoV-2 infection or severe COVID-19 disease per se, however, the risk is elevated in the presence of comorbidities, higher age, greater MS-associated disability, progressive disease course, and ongoing treatment with certain disease-modifying therapies (DMT) (1) (2) (3) (4) . Early initiation of treatment with high-efficacy DMT is the single most important factor in reducing long-term disability in pwMS (5) . Specific DMTs are, however, associated with an increased risk of infections (6) . Expert organizations worldwide recommend that all pwMS should be vaccinated against COVID-19 (7). There is increasing evidence of reduced humoral immunity after two doses of mRNA-COVID-19 vaccines among patients treated with anti-CD20 therapy (rituximab, ocrelizumab) or fingolimod (8, 9) . A beneficial effect of three doses of mRNA-COVID-19 vaccines has been observed in solid-organ transplant recipients (10) . However, the effect of a third vaccine dose on anti-SARS-Cov 2 IgG antibody levels in pwMS is largely unknown. We report results from a study designed to assess the immunogenicity and the safety of a third dose of COVID-19 mRNA vaccine in pwMS treated with anti-CD20 therapy or fingolimod.

The study was approved by the Norwegian, South-Eastern Regional Ethical Committee (Ref. Nr. 200631 ) and the Norwegian Medicines Agency (EudraCT Number: 2021-003618-37). All participants gave written, informed consent.

Study population: All anti-CD20-or fingolimod-treated pwMS with low or absent humoral immunity after two mRNA-COVID-19 vaccine doses were invited to the study. Inclusion criteria were MS diagnosis, signed informed consent, completed COVID-19-vaccination (i.e., two vaccine doses or past COVID-19 and one vaccine dose) and SARS-CoV-2 SPIKE RBD IgG <70 arbitrary units (AU) 3-12 weeks after full vaccination.

Testing of humoral immune response: Antibodies to full length Spike (HexaPro) from SARS-CoV-2 and the receptor-binding domain (RBD) were measured using a bead-based flow cytometric assay (11) in all included patients 3-12 weeks after full vaccination and 3-5 weeks after revaccination. Post-immunization IgG titers were used as a correlate of protection (12) , and reduced immunity was assumed in cases of IgG < 70 AUcorresponding to a lower level than found in 99% of healthy vaccinated subjects (9) . IgG levels < 5 AU were defined as no antibody response, while IgG levels between 5-70 AU were defined as weak antibody response. Calibration to the WHO international standard showed that 70 AU corresponds to approximately 40 Binding Antibody Units per milliliter (BAU/ml).

Data collection: Demographic, disease-, treatment-and vaccination-specific variables were acquired through a digital questionnaire completed by all patients and from patient journals. Information regarding side-effects were collected 3-5 weeks after revaccination. Information regarding COVID-19-vaccines was extracted from the Norwegian Immunization Registry.

Statistics: Continuous and categorical variables were compared using Mann-Whitney and Fisher's exact tests, respectively. A p value less than 0.05 was considered statistically is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted October 18, 2021. ; https://doi.org/10.1101/2021.10.15.21264977 doi: medRxiv preprint significant. Correlations were assessed by Spearman p. Statistical analysis was conducted using SPSS ® version 26 (SPSS Inc., Chicago, USA).

Of 175 invited pwMS, 130 patients (100 using rituximab, 1 ocrelizumab, and 29 fingolimod) had signed informed consent, completed COVID-19-revaccination (with a third dose of mRNA-COVID-19 vaccine), filled out digital questionnaire regarding side-effects, and underwent testing of humoral immune response before October 1 st 2021. Demographic and background variables are described in Table 1 .

While the majority of pwMS received the BNT162b2 vaccine (83% as the first, and 85% as the second jab) upon full vaccination, 85% received revaccination with the mRNA-1273 vaccine. The mean time between the last jab of full vaccination and revaccination was 94 days (STD 30.8 days) and 78 days (STD 18.2 days) in patients treated with anti-CD20 and fingolimod, respectively.

Mean levels of anti-SARS-CoV-2 SPIKE RBD IgG increased significantly in both treatment groups (anti-CD20: p < 0.001; fingolimod: p = 0.006) after revaccination. The proportion of patients with assumed protective humoral immunity (anti-SARS-CoV-2 SPIKE RBD IgG > 70) were 25% among patients using anti-CD20 therapy and 7% among those treated with fingolimod after revaccination ( Figure 1 ). Higher absolute lymphocyte (regardless of treatment) and CD19-B-cell counts (in patients receiving anti-CD20 therapy) were significantly associated with the development of protective humoral immunity (p = 0.03 in both cases).

Side-effects were observed in 63% of pwMS treated with anti-CD20 therapy and in 38% treated with fingolimod. The most common side-effects were transient local pain and fatigue in both groups. No patients experienced serious adverse effects after revaccination ( Table  2 ). The mean absolute lymphocyte count was significantly higher in patients reporting sideeffects, compared to those who did not (p = 0.03).

We present the first results of immune responses to COVID-19 revaccination in pwMS treated with anti-CD20 therapy or fingolimod. Our results show that a third dose of mRNA-COVID-19 vaccine was associated with modestly increased levels of anti-SARS-CoV-2 SPIKE RBD IgG antibodies in patients with reduced protective humoral immunity prior to reimmunization. Revaccination increased the proportion of patients with protective humoral immunity in both groups, and this effect was more pronounced among patients using anti-CD20 therapy.

Earle and colleagues found a robust correlation between neutralizing IgG titer and efficacy and between binding antibody titer and efficacy, despite geographically diverse study populations, and despite use of different endpoints, assays, convalescent sera panels and manufacturing platforms (12) . Together with evidence from natural history studies and animal models, their results support the use of post-immunization IgG titers as the basis for establishing a correlate of protection for COVID-19 vaccines.

Only 21% of our patients developed antibody levels where protective immunity can be assumed, hence, the clinical significance and the effect of a third vaccine dose remains is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted October 18, 2021. ; https://doi.org/10.1101/2021.10.15.21264977 doi: medRxiv preprint unclear. On the other hand, it may be important that 25% of those treated with anti-CD20 therapy acquired assumed protective humoral immunity, as these patients have an approximately three-fold risk of developing serious COVID-19 (2).

Patients with higher absolute lymphocyte counts seems to have a better response and pwMS with anti-CD20 therapies should probably be revaccinated shortly before the next treatment course is planned (9) . If disease activity allows, one might also consider widening treatment intervals to increase the probability of response to vaccination.

The rate of side-effects was higher in pwMS using anti-CD20 therapy compared to those treated with fingolimod, however, no serious adverse events were encountered and revaccination can be considered safe.

Our results are based on short-term follow-up of a limited number of patients. Long-term follow-up is undoubtedly of great importance, especially when the endpoints (e.g., antibody titers) are dynamic. Furthermore, we only report data regarding IgG responses as a correlate of humoral immunity, while the adaptive immune response to SARS-CoV-2 seems to depend also on cellular responses (13) . Finally, we do not report on neither the durability of the response or the clinical effect of revaccinations.

Conclusions: Revaccination (i.e., administration of a third dose of mRNA-COVID-19 vaccine) of anti-CD20-or fingolimod-treated pwMS with low antibody levels after two mRNA-COVID-19 vaccine doses improves protective humoral immunity. The effect of a third vaccine dose is limited and more prominent among those treated with anti-CD20 therapy. Our results show that revaccination can be considered safe, and hence, indicated to reduce the risk of serious COVID-19. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint Hospitalisation 0 (0) 0 (0) 0 (0) MS-relapse 0 (0) 0 (0) 0 (0) IQR, Interquartile range; V1/2/3, first/second/third vaccine dose; S2-3, antibody sample after V2 and V3, respectively is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted October 18, 2021. ; https://doi.org/10.1101/2021.10.15.21264977 doi: medRxiv preprint Figure 1 . The development of anti-SARS-CoV-2 SPIKE RBD IgG levels in anti-CD20 or fingolimod treated patients with multiple sclerosis undergoing revaccination. S2-3, antibody sample after second and third vaccine dose, respectively.

. CC-BY-NC-ND 4.0 International license It is made available under a perpetuity.

is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted October 18, 2021. ; https://doi.org/10.1101/2021.10.15.21264977 doi: medRxiv preprint

Outcomes and Risk Factors Associated With SARS-CoV-2 Infection in a North American Registry of Patients With Multiple Sclerosis

Disease-Modifying Therapies and Coronavirus Disease 2019 Severity in Multiple Sclerosis

Clinical Characteristics and Outcomes in Patients With Coronavirus Disease 2019 and Multiple Sclerosis

Increased rate of hospitalisation for COVID-19 among rituximab-treated multiple sclerosis patients: A study of the Swedish multiple sclerosis registry

Association of Initial Disease-Modifying Therapy With Later Conversion to Secondary Progressive Multiple Sclerosis

Infection Risks Among Patients With Multiple Sclerosis Treated With Fingolimod, Natalizumab, Rituximab, and Injectable Therapies

Update on the management of multiple sclerosis during the COVID-19 pandemic and post pandemic: An international consensus statement

Humoral immune response to COVID-19 mRNA vaccine in patients with multiple sclerosis treated with high-efficacy disease-modifying therapies

Humoral immunity to SARS-CoV-2 mRNA vaccination in multiple sclerosis: The relevance of time since last rituximab infusion and first experience from sporadic revaccinations

Three Doses of an mRNA Covid-19 Vaccine in Solid-Organ Transplant Recipients

Systemic complement activation is associated with respiratory failure in COVID-19 hospitalized patients

Evidence for antibody as a protective correlate for COVID-19 vaccines

Humoral and T-Cell Response to SARS-CoV-2 Vaccination in Patients With Multiple Sclerosis Treated With Ocrelizumab

Acknowledgements: We express our gratitude to Lars Skattebøl, Einar August Høgestøl, Rebecca Cox, the Bergen COVID-19 Group, and the Coalition for Epidemic Preparedness Innovations for their cooperation and support.

M. König