Herpes zoster and Janus kinase inhibition in rheumatology and gastroenterology patients: managing risk and vaccination.

Patients with chronic inflammatory diseases, such as rheumatoid arthritis (RA), psoriatic arthritis (PsA) and ulcerative colitis (UC), have an increased risk of herpes zoster (HZ) infection, compared with the general population. This risk is further increased by the use of immunomodulatory therapies, with a higher incidence of HZ reported in patients receiving Janus kinase (JAK) inhibitors, compared with those receiving other immunomodulatory or biological therapies. Tofacitinib is an oral JAK inhibitor for the treatment of RA, PsA and UC. In this narrative review, we discuss the effects of tofacitinib and other JAK inhibitors on HZ risk in patients with RA, PsA and UC, and strategies for risk management. We also discuss current UK guidelines for HZ vaccination in healthy individuals and patients with chronic inflammatory diseases, consider selected international guidelines, and review current HZ vaccination strategies.