Anti-JC virus serostatus changes before and during the COVID-19 pandemic in US patients with multiple sclerosis treated with natalizumab

ABSTRACT

Introduction: Natalizumab, a humanized monoclonal antibody approved to treat relapsing forms of multiple sclerosis, is associated with increased risk of progressive multifocal leukoencephalopathy, a rare, potentially deadly opportunistic infection of the brain by JC virus (JCV). Masking and social distancing in the United States (US) during the coronavirus disease 2019 (COVID-19) pandemic profoundly attenuated the spread of seasonal influenza in 2020-2021. The mode of JCV transmission is not well defined, and the pandemic offered a unique epidemiological opportunity to evaluate if isolation and masking practices enacted during the COVID-19 pandemic affected JCV transmission. Objective(s) To assess changes in the proportion of patients who converted to a positive anti-JCV antibody (Ab) serostatus before and during the COVID-19 pandemic. Method(s) Data were extracted from the TOUCH database for 22,375 patients treated with natalizumab in the United States (US) and with available anti-JCV Ab record information in the defined analysis population between 2017 and March 31, 2022. Anti-JCV Ab serostatus was determined by STRATIFY JCV DxSELECT. Serostatus change, defined as a change from anti-JCV seronegative status to seropositive, was assessed in annual epochs from April 1 to March 31. Patients were included in a given year if they had received >=1 dose of natalizumab in that year, had >=1 anti-JCV record 3 months prior to April 1 and also had >=1 anti-JCV Ab record post April 1 of that year. US regions examined (Northeast, South, Central and West) were determined using infusion site ZIP codes. Result(s) From April 1, 2017 to March 31, 2018, anti-JCV Ab serostatus change was observed for 7.7% of patients, with serostatus change of 7.4% and 7.4% of patients in the following 2 years (2018-2019 and 2019-2020). During the first and second years of the COVID-19 pandemic (2020-2021 and 2021-2022), 7.3% and 7.2% of patients' serostatus changed, respectively. There were no significant differences in serostatus change by US region. Conclusion(s) The proportion of natalizumab patients with anti-JCV Ab serostatus change did not significantly differ during the first 2 years of the COVID-19 pandemic compared with the 3 prior years. These results suggest that, in contrast to seasonal influenza, masking and social distancing had no discernable effect on JCV serostatus changes. If not spread through social contact, further studies are needed to understand how JCV is transmitted.