Hospitalisations and humoral COVID-19 vaccine response in vaccinated rituximab-treated multiple sclerosis patients.

BACKGROUND: Patients with multiple sclerosis (MS) treated with anti-CD20 therapies such as rituximab may have increased risk of severe COVID-19 disease. Vaccination induces protective immunity, but humoral vaccine response is known to be attenuated in rituximab-treated MS-patients-patients, which has indicated a need for real world data on severe morbidity and mortality from COVID-19 after vaccination. METHODS: Rituximab-treated patients treated at Haukeland University Hospital were identified through the National MS Registry and invited to participate in the study by giving a consent and providing a blood sample 3 weeks or later after ordinary COVID-19- vaccination, i.e. 2 doses given with a standard interval of 3 weeks. Blood samples were analysed with Enzyme-Linked Immunosorbent assay (ELISA) to evaluate humoral vaccine response with screening test against receptor-binding domain (RBD) and confirmatory Spike IgG-specific ELISA. A haemagglutination test (HAT) was performed as a marker of neutralizing antibodies. Patient serum concentration of rituximab were quantified using liquid chromatography tandem mass spectrometry (LC-MS/MS). Registry data from the Norwegian MS registry and information on hospitalization from patient records were collected and linked to laboratory results. RESULTS: 111 patients were included in the study. A total of 7 (6.3%) were hospitalized due to COVID-19 disease during the observation period. No patient was admitted to ICU and there were no deaths. 34.2% did not have detectable titre of SARS CoV-2 Spike IgG antibodies, 72.1% did not have a detectable titre of SARS CoV-2 RBD antibodies, and 88.2% did not have a detectable HAT titre. There was a correlation between hospitalisation and the absence of SARS CoV-2 Spike IgG antibody titre, and between hospitalisation and MS disease duration, as well as between spike IgG antibody titre and CD19 B-cell count, time since last rituximab infusion, cumulative rituximab treatment time and total IgG level in the patients. CONCLUSION: A substantial proportion of rituximab-treated MS-patients-patients did not have detectable humoral vaccine responses after 2 doses of COVID-19 vaccination. Despite this, the cumulative percentage of patients hospitalized with COVID-19 disease throughout the observation period of 22 months was low, and no patients required ICU treatment. The results support that vaccinated MS-patients treated with rituximab have a protective effect against serious Covid-19 infection.

BCG vaccination and multiple sclerosis risk: A Norwegian cohort study.

INTRODUCTION: Bacillus Calmette-Guérin (BCG) vaccination induces long-lasting effects on the adaptive and innate immune systems and prevents development of experimental autoimmune encephalomyelitis and possibly also inflammatory disease activity in multiple sclerosis (MS). OBJECTIVE: The objective is to examine if BCG given in early adulthood decreases MS risk. METHODS: From 791,369 (52% females) Norwegians participating in a national tuberculosis screening program from 1963 to 1975, we collected information on BCG vaccination and tuberculosis disease status. Later, MS disease was ascertained through both the Norwegian MS Registry and Biobank and the Norwegian Death Registry. We used logistic regression models to assess the relationship between BCG vaccination and MS risk. RESULTS: In those BCG vaccinated, mean age at vaccination was 15.6 (standard deviation (SD) = 5.5) years. A total of 2862 (65% females) MS cases were retrieved. Overall, we found no association between MS risk and BCG vaccination. Compared to non-BCG-vaccinated individuals with no signs of tuberculosis infection, odds ratio (OR) for MS was 1.00 (95% confidence interval (CI) = 0.80-1.25) in the BCG-vaccinated group. In those not BCG vaccinated because of latent tuberculosis infection, the corresponding OR was 0.86 (95% CI = 0.66-1.13). CONCLUSION: We found no evidence of BCG vaccination or latent tuberculosis infection in young adulthood being linked to MS risk.