A large study adds to our knowledge on the topic.

Immunisations are beneficial for people with multiple sclerosis, particularly those taking immunocompromising medications (NEJM JW Neurol Aug 29 2019 and Neurology 2019; 93: 584-594). Investigators used the French System of National Health Databases to identify patients with multiple sclerosis who received vaccination to determine risk for disease flare-up requiring hospitalisation. They identified a cohort of 106,523 patients with multiple sclerosis who were followed for a mean of nine years.

One-third of the cohort were hospitalised for multiple sclerosis relapses. The odds for vaccine exposure in the 60 days before the hospitalisation for relapse was 1.0 (95% confidence interval, 0.92–1.09) for all vaccines. Similar results were observed for DTP/polio/Haemophilus influenzae, influenza and pneumococcal vaccines. No differences were found based on sex or age. 

Comment: Consistent with prior studies, this large epidemiological analysis of data from a national health system over a prolonged time shows no increased risk for multiple sclerosis relapse with vaccination. Some patients may have a pseudo-relapse after vaccine from fever, which may manifest as fatigue, weakness, spasticity or other symptoms. Such pseudo-relapses can be managed conservatively with antipyretics.

Robert T. Naismith, MD, Professor of Neurology, Washington University, St. Louis, USA.

Grimaldi L, et al. Vaccines and the risk of hospitalization for multiple sclerosis flare-ups. JAMA Neurol 2023; 80: 1098-1104.

This summary is taken from the following Journal Watch title: Neurology.