Table 3.

Key aspects about the immunization of pwMS.

1. In MS patients with or without disease-modifying treatment (DMT), vaccines are not associated with an increased risk of relapses or disability. 2. In pwMS receiving sphingosine-1-phosphate modulators and anti-CD20, the production of antibodies is lower as compared to non-treated patients or patients receiving interferons, and the achieved seroprotection after vaccination can be reduced. 3. There is limited data about the protection after vaccination in patients treated with alemtuzumab and cladribine. However, due to the drug’s mechanism of action, a reduced seroprotection could be expected until a complete immune reconstitution is achieved. 4. An evaluation of the immunization status is recommended for all pwMS, regardless of initial therapeutic plans to minimize risks. Ideally, vaccination should be performed at the time of diagnosis or in the early stages of the disease. 5. In pwMS experiencing a relapse, vaccination should ideally be delayed until clinical resolution or stabilization. 6. For non-treated pwMS or those receiving immunomodulatory treatment who are planning to start any immunosuppressive therapy: Inactivated vaccines can be administered any time, but ideally at least 2 weeks before treatment onset to ensure a complete immune response. Live attenuated vaccines should be administered at least 4 weeks before treatment onset, 6 weeks for ocrelizumab and alemtuzumab. 7. Live attenuated vaccines: Can be safely used in pwMS without DMT or in those receiving immunomodulatory treatments. Should ideally be avoided in pwMS who are receiving the following immunosuppressive therapies (dimethyl fumarate and natalizumab). Should be avoided in MS patients receiving dimethyl fumarate a , teriflunomide, sphingosine-1-phosphate (S1 P) modulators, anti-CD20 monoclonal antibodies, and before immune restoration for cladribine and alemtuzumab, due to the potential risk of developing vaccine-related infections 8. In pwMS who receive a short-term pulse of high-dose steroid treatment, live attenuated vaccines should be postponed for 1 month. Ideally, inactivated vaccines should also be delayed for 1 month, but can be administered any time. 9. Adult and pediatric pwMS should receive those vaccines included in the corresponding routine vaccination schedule for the general population. 10. In pregnant women with MS, vaccination is recommended, as in the general population, to prevent potential infections with a high impact on maternal and infant morbidity and mortality. 11. PwMS, specially those who are candidates for/or on immunosuppressive therapies or those with a significant disability should receive yearly influenza vaccination and pneumococcal vaccination (following guidelines applicable in each country) 12. In pwMS who are candidates for/or on immunosuppressive therapies, other vaccines with more restrictive indications should be considered: Human papillomavirus vaccine in women and men with MS b who are scheduled to receive treatment with alemtuzumab, fingolimod, cladribine, or anti-CD20, independently of their age.   Herpes zoster inactivated vaccine in patients over 18 years of age c who are scheduled to receive any treatment with a high risk of herpes infections.   Hepatitis B in non-immune high-risk patients, especially those who are scheduled to receive treatment with anti-CD20.

^a.If absolute lymphocyte counts < 800/mm³ (grade 2 and 3 lymphopenia).

^b.There can be limitations and variations regarding upper age limit depending on the country and the Summary of product characteristics.

^c.With a background of chickenpox disease or live-attenuated varicella vaccination (otherwise consider varicella immunization). pwMS, people with multiple sclerosis.