Vaccination Strategies in Atopic Dermatitis Patients Treated With <scp>JAK</scp> Inhibitors

Janus kinase inhibitors (JAK-i) brought a breakthrough in the treatment of atopic dermatitis. Overall, JAK-i (abrocitinib, baricitinib, and upadacitinib) is an effective therapeutic option with an acceptable safety profile, due to their immunomodulatory effects. Careful consideration is needed with respect to infection risk and vaccination timing. Inhibition of JAK1/2 modulates cellular cytotoxicity by blocking the interferon-γ signaling pathway and may reduce the effectiveness of immune responses against viruses and intracellular bacterial pathogens [1]. As JAK inhibitor therapy may trigger the reactivation of certain infections, vaccination plays a key role in ensuring treatment safety. Due to the limited data on vaccinating JAK-i-treated patients with atopic dermatitis, recommendations are based on data derived from other immune-mediated inflammatory diseases, such as rheumatoid arthritis and psoriasis, as well as on the approved product information. In this context, Ara-Martín and colleagues present a practical recommendation for adult and adolescent patients with atopic dermatitis on vaccination that is readily applicable in everyday dermatological practice [2]. Although the article is written within the context of the Spanish healthcare system, it highlights the urgent need for the development of an international consensus. The American Academy of Dermatology recommends that, when feasible, all indicated live vaccines (e.g., measles-mumps-rubella, varicella) should be administered prior to initiation of JAK inhibitor therapy, as live attenuated vaccines are contraindicated during active treatment [3]. If administration is unavoidable, JAK inhibitor therapy should be temporarily discontinued according to the drug's half-life, and vaccination should ideally be administered at least 4 weeks prior to treatment initiation [2]. Inactivated vaccines can be safely administered during therapy. Annual influenza vaccination should be routinely offered to all patients, with intramuscular administration preferred. Pneumococcal vaccination is recommended for all patients with atopic dermatitis aged 18 years or older who are receiving JAK inhibitor therapy. The preferred schedule consists of the 13-valent pneumococcal conjugate vaccine, followed by the 23-valent pneumococcal polysaccharide vaccine after 12 months, with booster doses administered every 5 years thereafter. Hepatitis B vaccination is recommended for all patients initiating JAK inhibitor therapy with unknown or negative hepatitis B serology, given the risk of viral reactivation [2]. Herpes zoster vaccination is of particular importance, as viral reactivation is listed as a common adverse event in the prescribing information of these agents. In head-to-head trials, patients with atopic dermatitis treated with upadacitinib showed higher incidence rates of herpes zoster compared with those treated with dupilumab [4]. Overall, the incidence of herpes zoster infections in patients with atopic dermatitis receiving oral JAK inhibitors remained below 3%, with most cases being mild to moderate in severity [5]. The recombinant zoster vaccine is specifically recommended for adults who are immunocompromised or are scheduled to receive immunosuppressive medications [3]. For adolescent patients, Ara-Martín et al. recommend the routine administration of inactivated influenza, pneumococcal, and COVID-19 vaccines, as well as verification of measles–mumps–rubella and varicella immunity prior to initiating JAK inhibitor therapy. In case of acute disease flares, a minimum of 2 weeks of topical corticosteroid therapy is recommended before vaccination. When feasible, vaccines should be administered 2 weeks (for inactivated vaccines) or 4 weeks (for live attenuated vaccines) prior to initiating JAK inhibitor therapy [2]. Before initiating JAK inhibitor therapy, careful screening and review of the patient's vaccination status should be routinely performed. Hepatitis B serology and tuberculosis screening should be routinely performed, and preventive treatment initiated when indicated. From a practical clinical standpoint, inactivated vaccines can be administered safely without interrupting JAK inhibitor therapy, whereas live attenuated vaccines should generally be avoided unless temporary treatment interruption is feasible. Vaccination decisions should be made based on the available recommendations and individualized for each patient's infection risk and clinical context. The author has nothing to report. The author declares no conflicts of interest. Research data are not shared.