@article{MRA, author = {Lorna Galleguillos and Ricardo Alonso and Andrea Alarcon and Jorge Villacura and Marianne Kägi and Marianella Hernández and Violeta Díaz and Jorge Barahona}, title = { The story of protective humoral immunity against COVID-19 in a chilean cohort of multiple sclerosis patients: Vaccines are necessary}, journal = {Medical Research Archives}, volume = {12}, number = {9}, year = {2024}, keywords = {}, abstract = {Background: There is scarce data in Latin America about how the protective humoral immunity behaves in patients that received an inactivated COVID-19 or mRNA vaccine or boosters in people with Multiple Sclerosis (pwMS). Objective: To evaluate humoral response to COVID-19 vaccines in a cohort of Chilean pwMS treated with high efficacy therapies (HET) and the effect of a booster. Methods: Observational cohort study of pwMS receiving mRNA or inactivated (CoronaVac) COVID-19 vaccines and a booster with mRNA vaccine 5 months after. IgG anti spike was determined in 4 groups: cladribine, anti-20 (rituximab or ocrelizumab), alemtuzumab and reference group. Results: Hundred and thirty-two patients: 24.7% on cladribine and 13% on ocrelizumab, 84.9% received CoronaVac.  No significant differences between time from last dose of HET and IgG production. Significant differences on absolute lymphocyte count between cladribine and antiCD20 (p<0.01). Anti-CD20 produced the lowest 4weeks post-vaccine IgG titers. 72.5% pwMS had Protective humoral immunity (PHI) at 4weeks but only 18.5% of the antiCD20 group did have it. The 5 months post-vaccine IgG titers were evaluated in 69 patients; all kept PHI; 26.6% of the antiCD20 group with no previous PHI, received a booster with mRNA vaccine and did produce PHI after it. Conclusions: CoronaVac produce PHI in pwMS treated with HET in the analyzed cohort, except for Anti-CD20 therapies in our cohort. The booster in the anti CD20 therapy with no PHI after 2 doses of the COVID-19 vaccine had a small impact in the IgG anti spike production. Further studies are needed in our cohort to understand the kinetics of the PHI with inactivated vaccines and the boosters.}, issn = {2375-1924}, doi = {10.18103/mra.v12i9.5641}, url = {https://esmed.org/MRA/mra/article/view/5641} }