Inactivated vaccine receipt during natalizumab treatment safe, immunogenic in MS patients

For patients with multiple sclerosis (MS) who are receiving treatment with natalizumab, getting shots with inactivated vaccines is safe and immunogenic, with the positive results persisting regardless of the duration of natalizumab therapy, as shown in a study.

A total of 60 adult MS patients (mean age 43.2 years, 73.3 percent women, mean disease duration 17.0 years) participated in the self-controlled, prospective cohort study. These participants had completed immunization for hepatitis B virus (HBV), hepatitis A virus (HAV), and COVID-19 during natalizumab therapy. At the time of vaccine administration, 48 patients had been on natalizumab treatment for more than a year (long-term group) and 12 had been receiving treatment for ≤1 year (short-term group).

Researchers collected demographic, clinical, and radiological data during the year before vaccination (prevaccination period) and the year after vaccination (postvaccination period). The main study outcomes were seroprotection rates and postvaccination immunoglobulin G titres for each vaccine within both periods. Other outcomes of interest included differences in annualized relapse rate (ARR), new T2 lesions (NT2L), Expanded Disability Status Scale (EDSS) scores, and John Cunningham virus (JCV) serostatus.

The vast majority of the population (93 percent, 95 percent confidence interval [CI], 86–98) showed evidence of immunity to all three viruses. Individual vaccines achieved similar seroprotection rates, with 92 percent for HAV (95 percent CI, 73–99), 93 percent for HBV (95 percent CI, 76–99), and 100 percent for the COVID-19 messenger RNA vaccine (95 percent CI, 84–100).

Between the pre- and postvaccination periods, significant reductions were observed in the mean ARR (0.28 vs 0.01; p=0.004) and median NT2L (5.00 vs 0.81; p=0.01). Meanwhile, disability accumulation remained unchanged (median EDSS score: 3.5 vs 3.5; p=0.62).

The safety and immunogenicity were similar for all vaccines in terms of the duration of natalizumab treatment.