Severe Autoimmune Adverse Events Post Herpes Zoster Vaccine: A Case-Control Study of Adverse Events in a National Database.

Zoster vaccine is recommended to reduce the incidence of herpes zoster and its complication of postherpetic neuralgia in older adults. However, there have been reports of autoimmune side effects post vaccination. We therefore aim to investigate the possible relationship of severe autoimmune adverse events (arthritis, vasculitis, systemic lupus erythematosus, thrombocytopenia, alopecia, Guillain-Barre syndrome, optic neuritis and multiple sclerosis) post zoster vaccination with a matched case-control study of reported events in the Vaccine Adverse Event Reporting System (VAERS). Our study showed no significantly increased risks of severe autoimmune adverse events, except arthritis and alopecia, after vaccination. Compared to the unexposed, patients with zoster vaccination had 2.2 and 2.7 times the odds of developing arthritis and alopecia, respectively (P<0.001 and P=0.015, respectively). However, almost none of these events was life threatening. Zoster vaccine is, therefore, relatively safe and unlikely to exacerbate or induce autoimmune diseases. Given its benefits and safety but low coverage, dermatologists and primary care physicians should encourage zoster vaccine use in elderly patients, including selected patients with autoimmune diseases.