Influenza vaccines do not cause multiple sclerosis (MS). Other vaccines currently routinely recommended to the general population in the U.S.* have not been shown to cause multiple sclerosis (MS).
Most studies described in the 2012 report by the Institute of Medicine (IOM), now called the National Academy of Medicine (NAM), found no association between vaccination and MS, whether assessing onset [1-5] or relapse [6, 7] in adults, or onset [1, 8] or relapse  in children; however, these studies did not provide convincing evidence due to a lack of validity and precision . Studies published since the 2012 IOM report focusing on the pandemic H1N1 influenza vaccine Pandremix [11-13], quadrivalent HPV vaccine (Gardasil) [14-16] and hepatitis B vaccine  have also found no association with MS. A white paper on influenza vaccine safety published in 2015 concluded that while each individual study had relatively low power, as a group they provide consistent evidence against a causal association between influenza vaccine in adults and MS onset or relapse; although the data are more limited in children, there is no signal to indicate concern . A recent systematic review found no increase in risk of development of MS after vaccination against hepatitis B, HPV, influenza, MMR, tetanus, diphtheria, polio, smallpox, or BCG vaccines .
Hypersensitivity reactions triggered by autoimmunity, genetics or environmental factors such as viral infection are often incriminated in the destruction of the hostís myelin basic protein (MBP) and other antigens . Similarities in features of MS and other demyelinating disorders have been described and some subjects with the diagnosis of Acute Disseminated Encephalomyelitis (ADEM) have had recurrences and progressed to MS [20, 21]. One possible mechanism is molecular mimicry, which refers to the possibility that similar epitopes shared between self-peptides and foreign peptides (introduced via infection or immunization) inadvertently cause the activation of autoreactive T or B cells, leading to autoimmunity. Of the many vaccines assessed for a possible association with MS, the hepatitis B vaccine has captured the most interest, because molecular mimicry has been demonstrated in rabbits between hepatitis B viral polymerase and the part of the MBP that leads to encephalitis . This suggests that infection with a virus showing similarities with MBP regions associated with the development of encephalitis could induce MS through molecular mimicry. However, the IOM concluded that there was no mechanistic evidence for an association between vaccination and MS, as the publications reviewed provided no evidence beyond a temporal association .
* These conclusions do not necessarily consider vaccines recommended only for special populations in the United States such as Yellow Fever vaccine (international travelers) or Smallpox vaccine (military personnel).
1. Ahlgren C, Toren K, Oden A, Andersen O. A population-based case-control study on viral infections and vaccinations and subsequent multiple sclerosis risk. Eur J Epidemiol 2009;24:541-52.
2. Ascherio A, Zhang SM, Hernan MA, et al. Hepatitis B vaccination and the risk of multiple sclerosis. The New England journal of medicine 2001;344:327-32.
3. DeStefano F, Verstraeten T, Jackson LA, et al. Vaccinations and risk of central nervous system demyelinating diseases in adults. Arch Neurol 2003;60:504-9.
4. Hernan MA, Jick SS, Olek MJ, Jick H. Recombinant hepatitis B vaccine and the risk of multiple sclerosis: a prospective study. Neurology 2004;63:838-42.
5. Hocine MN, Farrington CP, Touze E, et al. Hepatitis B vaccination and first central nervous system demyelinating events: reanalysis of a case-control study using the self-controlled case series method. Vaccine 2007;25:5938-43.
6. Confavreux C, Suissa S, Saddier P, Bourdes V, Vukusic S. Vaccinations and the risk of relapse in multiple sclerosis. Vaccines in Multiple Sclerosis Study Group. The New England journal of medicine 2001;344:319-26.
7. Miller AE, Morgante LA, Buchwald LY, et al. A multicenter, randomized, double-blind, placebo-controlled trial of influenza immunization in multiple sclerosis. Neurology 1997;48:312-4.
8. Mikaeloff Y, Caridade G, Rossier M, Suissa S, Tardieu M. Hepatitis B vaccination and the risk of childhood-onset multiple sclerosis. Archives of pediatrics & adolescent medicine 2007;161:1176-82.
9. Mikaeloff Y, Caridade G, Assi S, Tardieu M, Suissa S. Hepatitis B vaccine and risk of relapse after a first childhood episode of CNS inflammatory demyelination. Brain : a journal of neurology 2007;130:1105-10.
10. Institute of Medicine. In: Stratton K, Ford A, Rusch E, Clayton EW, eds. Adverse Effects of Vaccines: Evidence and Causality. Washington (DC): National Academies Press (US); 2012.
11. Bardage C, Persson I, Ortqvist A, Bergman U, Ludvigsson JF, Granath F. Neurological and autoimmune disorders after vaccination against pandemic influenza A (H1N1) with a monovalent adjuvanted vaccine: population based cohort study in Stockholm, Sweden. Bmj 2011;343:d5956.
12. Persson I, Granath F, Askling J, Ludvigsson JF, Olsson T, Feltelius N. Risks of neurological and immune-related diseases, including narcolepsy, after vaccination with Pandemrix: a population- and registry-based cohort study with over 2 years of follow-up. J Intern Med 2014;275:172-90.
13. Farez MF, Ysrraelit MC, Fiol M, Correale J. H1N1 vaccination does not increase risk of relapse in multiple sclerosis: a self-controlled case-series study. Multiple sclerosis (Houndmills, Basingstoke, England) 2012;18:254-6.
14. Chao C, Klein NP, Velicer CM, et al. Surveillance of autoimmune conditions following routine use of quadrivalent human papillomavirus vaccine. J Intern Med 2012;271:193-203.
15. Langer-Gould A, Qian L, Tartof SY, et al. Vaccines and the risk of multiple sclerosis and other central nervous system demyelinating diseases. JAMA neurology 2014;71:1506-13.
16. Scheller NM, Svanstrom H, Pasternak B, et al. Quadrivalent HPV vaccination and risk of multiple sclerosis and other demyelinating diseases of the central nervous system. Jama 2015;313:54-61.
17. Halsey NA, Talaat KR, Greenbaum A, et al. The safety of influenza vaccines in children: An Institute for Vaccine Safety white paper. Vaccine 2015;33 Suppl 5:F1-f67.
18. Mailand MT, Frederiksen JL. Vaccines and multiple sclerosis: a systematic review. Journal of Neurology 2016:1-16.
19. Pena JA, Lotze TE. Pediatric multiple sclerosis: current concepts and consensus definitions. Autoimmune diseases 2013;2013:673947.
20. Krupp LB, Tardieu M, Amato MP, et al. International Pediatric Multiple Sclerosis Study Group criteria for pediatric multiple sclerosis and immune-mediated central nervous system demyelinating disorders: revisions to the 2007 definitions. Multiple sclerosis (Houndmills, Basingstoke, England) 2013;19:1261-7.
21. Sejvar JJ, Kohl KS, Bilynsky R, et al. Encephalitis, myelitis, and acute disseminated encephalomyelitis (ADEM): case definitions and guidelines for collection, analysis, and presentation of immunization safety data. Vaccine 2007;25:5771-92.
22. Fujinami RS, Oldstone MB. Amino acid homology between the encephalitogenic site of myelin basic protein and virus: mechanism for autoimmunity. Science 1985;230:1043-5.