Traveling with MS – Is Vaccination a Limitation?
What about the need for vaccination when traveling abroad? Which vaccines should you be cautious about? And how to time vaccination concerning disease activity and the individual medications used in multiple sclerosis (MS) therapy?
When Benefits Outweigh Risks
Vaccination is generally a tricky topic for patients with autoimmune diseases, including MS, and opinions among doctors differ. Given that infections clearly increase MS activity, the benefits of vaccination are evident. However, vaccines themselves, due to their mechanism of action, also carry a small but present potential risk of relapse.
Vaccination is clearly indicated for patients starting treatment with certain disease-modifying drugs (DMDs). These substances have an immunomodulatory effect and are associated with a higher risk of certain infections and also poorer vaccine efficacy when conducted during or shortly after treatment. For example, sphingosine-1-phosphate (S1P) modulators (fingolimod, siponimod, ponesimod, ozanimod) are linked with a significant risk of varicella zoster (VZV) infection. Therefore, vaccination against this virus should precede therapy initiation if the patient has not had chickenpox and lacks sufficient protective antibody concentrations. The vaccination should ideally be administered at least 4 weeks in advance. A similar approach applies to tetanus vaccinations, although the risk of reduced vaccine efficacy during treatment is lower in this case. It is also recommended to consider vaccinating against human papillomavirus (HPV) before starting treatment, as cases of genital warts, dysplasia, and more advanced oncological findings on the cervix have been reported due to this virus. After discontinuing S1P modulators, further vaccinations should be delayed by at least 2 months.
The need for pre-treatment vaccination also applies to anti-CD20 antibodies (ocrelizumab, rituximab), alemtuzumab, and cladribine. As in the previous case, it is essential to vaccinate primarily against VZV, tetanus, and consider HPV vaccination for similar reasons. Vaccination should be completed 4–6 weeks before treatment initiation. If multiple vaccines are needed (such as against tetanus and VZV), it is advisable to leave at least 2-week intervals between applications.
When You Need to Jump on a Moving Train
Not always can vaccination be timed before therapy initiation. An example is the arrival of new vaccines against the SARS-CoV-2 coronavirus. Vaccination should always occur during disease stabilization, preceded by a control of existing IgG antibody titers. For rituximab and ocrelizumab, vaccination should occur 5 months after the last infusion. For alemtuzumab or cladribine therapy, it can be done no sooner than 6 months after the last pulse, or earlier, but only if the blood count has normalized. Following the administration of high-dose corticosteroids, vaccination should be postponed by at least 4 weeks.
Off to Adventure
When discussing the benefits of vaccinations against VZV or tetanus, the answer is almost unequivocal. But what about other vaccines? Currently, compared to the past, there is a much more positive approach to vaccination. However, the nature of the vaccine and the individual risk-benefit ratio must still be considered. There is no concrete evidence yet that any common vaccines (against influenza, hepatitis B, tick-borne encephalitis, or tuberculosis) increase the risk of relapse or disease progression. In general, it is important to exercise caution with live vaccines due to the risk of developing an infection in immunosuppressed patients.
The only problematic vaccine currently appears to be the one for yellow fever, which has shown a significant increase in relapse incidence in one study. Therefore, the necessity of traveling to sub-Saharan African countries (such as Angola, the Democratic Republic of the Congo, Niger, or Senegal), where this vaccination is mandatory, should be thoroughly discussed with the patient. It is advisable to carefully examine the recommendations before traveling; often, the infection risk relates to the entire state, although only a small part of the country may be associated with yellow fever outbreaks.
(dos)
Sources:
1. SPC of relevant medicinal products.
2. Updated recommendation by the committee section on vaccination against COVID-19. Section of Clinical Neuroimmunology and Liquorology ČNS ČLS JEP, March 6, 2021. Available at: www.czech-neuro.cz/sekce/sekce-klinicke-neuroimunologie-a-likvorologie/zapisy-vyboru
3. Mailand M. T., Frederiksen J. L. Vaccines and multiple sclerosis: a systematic review. J Neurol 2016; 264 (6): 1035–1050, doi: 10.1007/s00415-016-8263-4.
4. Farez M. F., Correale J., Armstrong M. J. et al. Practice guideline update summary: vaccine-preventable infections and immunization in multiple sclerosis. Neurol 2019; 93: 584–594, doi: 10.1212/WNL.0000000000008157
5 Farez M. F., Correale J. Yellow fever vaccination and increased relapse rate in travelers with multiple sclerosis. Arch Neurol 2011; 68 (10): 1267–1271, doi: 10.1001/archneurol.2011.131.4.
6. Vaccination and Travel Medicine Center. Destinations and Vaccinations. Available at: www.ockovani-zahranici.cz/downloads/destinace.pdf
Did you like this article? Would you like to comment on it? Write to us. We are interested in your opinion. We will not publish it, but we will gladly answer you.
