Breakthrough COVID-19 infection after vaccination in patients with NMOSD in Latin America: data from RELACOEM registry

ABSTRACT

Objective: The objective of the study was to evaluate the incidence of COVID-19 infections after vaccination in NMOSD patients included in RELACOEM, a LATAM registry of MS and NMOSD patients infected and vaccinated for COVID-19. Method(s) Retrospective cohort study developed between May 2021 to December 2021. The primary outcome was the appearance of infection during the follow up time (at least three months after complete vaccination (second dose)). Data was collected through the contact between the treating physician and the patient. Specific information was requested (vaccine received, dose, date, symptoms, COVID-19 infection, need for hospitalization, ventilatory assistance, treatment, and evolution). The primary objective of the analysis was to compare the incidence of breakthrough SARS-CoV-2 19 infections among the vaccinated pwMS in each DMT group. These conditions entail a PCR-confirmed test, and a time lag of at least 14 days from a full vaccination cycle (after the second vaccination dose). Cumulative incidence was reported by Kaplan Meier survival curves as well as incidence density. Result(s) A total of 49 NMOSD patients from eight countries in LATAM were included. Mean age was 43.8 +/-13 years. The most frequent treatment use was rituximab in 29 (59.2%). The mean follow up after the second dose was 149 +/- 32 days. Most frequent first and second dose received was Pfizer (28.6%), followed by Sinopharm (24.5%). During follow up a total of 2 COVID-19 cases were observed for a total exposure time of 8627 days. Cumulative incidence was 4.1% (SE 0.87%) with an overall incidence density of 2.31 x 10.000 patients/day (95%CI 1.13-3.71). Both cases occurred in patients under rituximab (2/29, exposure time 4208, IR 4.7 x 10,000 patients/day 95%CI 3.5-5.1). No hospitalizations were reported for both cases. Conclusion(s) We observed an ID of COVID-19 infection after vaccination of 2.31 x 10.000 patients/day in NMOSD patients.