Guideline Update Emphasizes Importance of Vaccinations for Patients With MS

A guideline update issued by the American Academy of Neurology states that patients with multiple sclerosis (MS) should receive all recommended vaccinations unless contraindicated.

The systematic review, which was published in Neurology, updates a guideline from 2002 on immunization and MS.¹ The new review addresses several important questions about vaccination and infectious disease in the population with MS, including the prevalence of such diseases, the potential risk of MS development or exacerbation associated with vaccination, and vaccine effectiveness in patients with MS.

The review authors did not find sufficient evidence to support or refute associations between (1) development of MS and a history of many vaccine-preventable infectious diseases (eg, diphtheria, measles, pertussis, polio), (2) development of MS and a history of several vaccinations (eg, diphtheria, hepatitis B, influenza, measles/mumps/rubella), (3) MS exacerbation and influenza, and (4) MS exacerbation and history of vaccination against tuberculosis, influenza, or tick-borne encephalitis.

They identified some evidence pointing to probable associations between some vaccination types (ie, human papillomavirus, pertussis, smallpox, tetanus toxoid) and a lower likelihood of a subsequent MS diagnosis. They also found evidence that patients with MS receiving certain therapies (ie, glatiramer acetate, fingolimod, mitoxantrone) may have a lower likelihood of protection from influenza vaccination, likely because immunosuppressive or immunomodulating (ISIM) agents reduce the body’s ability to mount an immune response to a vaccination.

Considering the new evidence available, the guideline authors recommended that clinicians should (1) discuss this evidence on vaccination with patients; (2) explore and address patients’ opinions, preferences, and questions to determine an optimal vaccine strategy; (3) recommend that patients with MS follow local vaccine standards unless a specific contraindication exists; (4) weigh local risks of preventable diseases when advising patients with MS about vaccination; and (5) recommend that patients with MS receive the influenza vaccine annually unless there is a specific contraindication.

These were each Level B recommendations, which are less strong than Level A “but are still associated with confidence in the rationale and a favorable benefit-risk profile,” the authors wrote.

Although a significant amount of new evidence has been incorporated into the updated guideline since the 2002 version, the authors noted remaining gaps in knowledge, often related to weaknesses in study design and methodology (eg, evaluations of vaccine effectiveness were mostly cohort studies, not randomized controlled trials) or limited generalizability (eg, samples including only patients who were ambulatory). There is also little, if any, evidence on the effects of certain ISIM therapies on immunization effectiveness.

However, the guideline authors felt that their recommendations are “sufficiently broad” because these agents frequently have similar mechanisms of action. They encouraged clinicians to review prescribing information (PI) from drug manufacturers to learn more about potential interactions with vaccines.

The 2 Level A recommendations included in the guidelines were that clinicians must (1) screen patients for infections before prescribing ISIM drugs according to the drugs’ PI and (2) screen for latent infections in high-risk patient populations before starting ISIM therapy, even if not mentioned in the drugs’ PI.

“As more ISIM agents are developed to manage chronic diseases such as MS, long-term prospective cohort studies are required to evaluate both the safety and effectiveness of immunizations in MS,” they concluded. “Simultaneous prospective cohort studies to evaluate the risks of infections in patients with MS and the effect of infections on short-term and long-term disability in patients with MS will help the risk-benefit analysis of immunization in this population.”

The authors hope that the guidelines will provide clarity for clinicians and reassurance for patients.

“We reviewed all of the available evidence and for people with MS, preventing infections through vaccine use is a key part of medical care,” said guideline lead author Mauricio F. Farez, MD, MPH, of the FLENI Institution in Buenos Aires, Argentina, in a statement.² “People with MS should feel safe and comfortable getting their recommended vaccinations.”

References

1. Farez MF, Correale J, Armstrong MJ, et al. Practice guideline update summary: vaccine-preventable infections and immunization in multiple sclerosis: report of the Guideline Development, Dissemination, and Implementation Subcommittee of the American Academy of Neurology [published online August 28, 2019]. Neurology. doi: 10.1212/WNL.0000000000008157.

2. AAN issues guideline on vaccines and multiple sclerosis [news release]. Minneapolis, MN: American Academy of Neurology; August 28, 2019. prnewswire.com/news-releases/aan-issues-guideline-on-vaccines-and-multiple-sclerosis-300908216.html. Accessed September 4, 2019.