Safety of COVID-19 vaccines in multiple sclerosis: A systematic review and meta-analysis

Abstract

Background Data are sparse regarding the safety of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines in patients with multiple sclerosis (MS). Objective To estimate (1) the pooled proportion of MS patients experiencing relapse among vaccine recipients; (2) the rate of transient neurological worsening, adverse events, and serious adverse events; (3) the previous outcomes of interest for different SARS-CoV-2 vaccine types. Methods Systematic review and meta-analysis of pharmacovigilance registries and observational studies. Results Nineteen observational studies comprising 14,755 MS patients who received 23,088 doses of COVID-19 vaccines were included. Mean age was 43.3 years (95% confidence interval (CI): 40–46.6); relapsing-remitting, secondary-progressive, primary-progressive MS and clinically isolated syndrome were diagnosed in 82.6% (95% CI: 73.9–89.8), 12.6% (95% CI: 6.3–20.8), 6.7% (95% CI: 4.2–9.9), and 2.9% (95% CI: 1–5.9) of cases, respectively. The pooled proportion of MS patients experiencing relapse at a mean time interval of 20 days (95% CI: 12–28.2) from vaccination was 1.9% (95% CI: 1.3%–2.6%; I2 = 78%), with the relapse risk being independent of the type of administered SARS-CoV-2-vaccine ( p for subgroup differences = 0.7 for messenger RNA (mRNA), inactivated virus, and adenovector-based vaccines). After vaccination, transient neurological worsening was observed in 4.8% (95% CI: 2.3%–8.1%) of patients. Adverse events and serious adverse events were reported in 52.8% (95% CI: 46.7%–58.8%) and 0.1% (95% CI: 0%–0.2%) of vaccinations, respectively. Conclusion COVID-19 vaccination does not appear to increase the risk of relapse and serious adverse events in MS. Weighted against the risks of SARS-CoV-2-related complications and MS exacerbations, these safety data provide compelling pro-vaccination arguments for MS patients.

Impact of COVID-19 vaccination or infection on disease activity in a radiologically isolated syndrome cohort: The VaxiRIS study

“…Finally, a recent meta-analysis of 19 studies gathering more than 14,000 MS patients concluded that COVID-19 vaccination was not associated with an increased risk of disease activity. 28 Conversely, two reports 20,25,27 and one case series 22 of 16 patients described MS relapses shortly after COVID-19 vaccination. Still, the timing between the vaccination and relapse occurrence was often very short, raising the question of a true causality between the two events.…”

“…Finally, a recent meta-analysis of 19 studies gathering more than 14,000 MS patients concluded that COVID-19 vaccination was not associated with an increased risk of disease activity. 28…”

“…Several studies explored disease activity after COVID-19 vaccination in MS patients. [20][21][22][23][24][25][26][27][28] Most results highlighted that vaccination was not associated with a higher risk of relapse. A multicentric observational study conducted in Italy 29 involving 324 patients with MS showed that Pfizer/BioNTech vaccine did not increase the short-term risk of acute exacerbations 2 months post-exposure.…”

Evaluation of the safety profile of COVID-19 vaccines in patients with MS, NMOSD, and MOGAD

“…In addition, only 4.4% (99/2261) of patients experienced a relapse after vaccination. A recent systematic review and meta-analysis of 19 studies comprising 14,755 SARS-CoV-2-vaccinated patients with MS also found that the pooled proportion of MS patients with relapse after vaccination was only 1.9% [16]. Moreover, the proportion of patients with serious adverse events was as low as 0.1%.…”

“…In addition, vaccination is a complex issue in this population considering that these patients are frequently subjected to immunomodulatory or immunosuppressive treatments. A number of recent studies of patients with MS have shown that COVID-19 vaccination does not increase the risk of clinical relapse and serious adverse events, suggesting favorable safety of COVID-19 vaccine in MS patients [14][15][16]. The issue of immunogenicity of COVID-19 vaccines in relation to MS medications has also been evaluated in some studies [17,18].…”