Safety, immunogenicity, efficacy, and acceptability of COVID-19 vaccination in people with multiple sclerosis: a narrative review

In the last two years, a new severe acute respiratory syndrome coronavirus (SARS-CoV) infection has spread worldwide leading to the death of millions. Vaccination represents the key factor in the global strategy against this pandemic, but it also poses several problems, especially for vulnerable people such as patients with multiple sclerosis. In this review, we have briefly summarized the main findings of the safety, efficacy, and acceptability of Coronavirus Disease 2019 (COVID-19) vaccination for multiple sclerosis patients. Although the acceptability of COVID-19 vaccines has progressively increased in the last year, a small but significant part of patients with multiple sclerosis still has relevant concerns about vaccination that make them hesitant about receiving the COVID-19 vaccine. Overall, available data suggest that the COVID-19 vaccination is safe and effective in multiple sclerosis patients, even though some pharmacological treatments such as anti-CD20 therapies or sphingosine l-phosphate receptor modulators can reduce the immune response to vaccination. Accordingly, COVID-19 vaccination should be strongly recommended for people with multiple sclerosis and, in patients treated with anti-CD20 therapies and sphingosine l-phosphate receptor modulators, and clinicians should evaluate the appropriate timing for vaccine administration. Further studies are necessary to understand the role of cellular immunity in COVID-19 vaccination and the possible usefulness of booster jabs. On the other hand, it is mandatory to learn more about the reasons why people refuse vaccination. This would help to design a more effective communication campaign aimed at increasing vaccination coverage among vulnerable people.