A review on the association between inflammatory myopathies and vaccination.

Several viruses and vaccines are among the environmental factors implicated as triggers of autoimmune inflammatory myopathies. Case histories report on the onset of dermatomyositis/polymyositis after immunization with various vaccines of patients with probable genetic predisposition. However, retrospective and epidemiological studies failed to ascertain an association between DM/PM and vaccines: no significant increase in the incidence of DM/PM was reported after large vaccination campaigns. The risk for vaccine-induced adverse events may be enhanced by adjuvants. Macrophagic myofasciitis is a novel inflammatory myopathy ascribed to an ongoing local immune reaction to a vaccine adjuvant. Isolated prospective studies showed that the administration of unadjuvanted, non-live vaccine to patients with DM/PM caused no short-term harmful effects to DM/PM immune processes. However, more research is warranted to clarify the incidence of vaccine-preventable infections, harmful effects of vaccination, and the influence of any immunomodulating agents on vaccination efficacy. Vaccination is an important disease prevention tool in modern medicine. This review does not address risk-benefit or cost-benefit analyses, and does not advocate the use of specific vaccines or vaccination programs. Despite a great deal of scientific uncertainty, the concept of a possible causal link between immunization and inflammatory myopathies should not be totally rejected.