Abstract Background Patients with inflammatory bowel disease(IBD)have a higher risk of varicella zoster virus infection (VZI) than the general population, largely due to immunosuppressive-biologic therapies. Preventing viral reactivation is a relevant clinical goal. The recombinant zoster vaccine (RZV, Shingrix) has shown high efficacy and good tolerability in the general population,but data in IBD are limited. Real-world evidence on its effectiveness and safety is needed to support vaccination strategies and guide clinical practice. The objective of the study was to assess the effectiveness and safety of the RZV in IBD. Methods From March 2023 to September 2024, consecutive IBDpatients who received the RZV Shingrix before starting or with ongoing biologics were prospectively enrolled across 9 tertiary IBDcenters. Effectiveness was assessed clinically and defined as the absence of VZI or HZ reactivation during the observation period. Safety outcomes included the occurrence of vaccine-related adverse events (AEs)—such as fever, arthralgia, and others—systematically recorded during the follow-up after each vaccine dose. Results A total of 420 IBD cases were included, comprising 215 (51.2%) with UC and 205 (48.8%) with CD. Most patients (95.8%) completed the VZV vaccination cycle. Biologic therapy was ongoing in 319 (75.9%) patients, more frequently in CD than UC (p 0.001). During a mean follow-up of 11.0 ± 1.2 months, VZV reactivation occurred in only 0.7% of patients, confirming a high clinical effectiveness of RZV in IBD. Overall, AEs were reported in 52.4% of cases, with the most common being arm pain (37.1%), followed by asthenia (16.0%) and fever (13.8%). No significant differences between UC and CD (54.4% vs 50.2%, p = 0.448), as for gender (p = 0.96), were found. AE occurrence was significantly associated with ongoing biologic therapy (56.9% vs 29.3% without, p = 0.009) and lower age (median 42 vs 45.5 years, p = 0.047). However, analyzing therapies by specific mechanism of action, no class of drug was associated with a higher AE risk compared to others. Logistic regression confirmed only biologics as an independent risk factor (OR1.84; 95%; p = 0.009). In the subgroup analysis comparing biologics to conventional or no therapy, only asthenia and joint pain were more common in patients on biologics (p 0.001 and p = 0.04, respectively). No serious AEs were reported. Conclusion RZV demonstrated a favorable safety profile in IBD patients, with only mild and self-limiting adverse events, more frequently observed in those receiving biologics. Notably, the very low rate of VZV reactivation (0.7%) over a mean follow-up of 11 months confirms the high effectiveness of RZV in this high-risk population. These findings support the integration of RZV into preventive strategies in IBD, particularly before or during immunosuppressive therapy. References: 1. Din S, Selinger CP, Black CJ, Ford AC. Systematic review with network meta-analysis: Risk of Herpes zoster with biological therapies and small molecules in inflammatory bowel disease. Aliment Pharmacol Ther. 2023 Mar; 57 (6): 666-675. 2. Nugent Z, Singh H, Targownik LE, Bernstein CN. Herpes Zoster Infection and Herpes Zoster Vaccination in a Population-Based Sample of Persons With IBD: Is There Still an Unmet Need? Inflamm Bowel Dis. 2019 Feb 21; 25 (3): 532-540. Conflict of interest: Castiglione, Fabiana: Honoraria from: Takeda, AbbVie, Celltrion, Johnsson Johnsson, Cadigroup, Sandoz, Pfizer, Lilly, Lionhealth, Nestlè Guarino, Alessia Dalila: No conflict of interest Pinchera, Biagio: No conflict of interest Spadaro, Giuseppe: No conflict of interest Zappulo, Emanuela: No conflict of interest Calabrese, Giulio: No conflict of interest Rispo, Antonio: None Testa, Anna: Consultant /Advisory board for Abbvie, J & J, Takeda, Ferring Nardone, Olga Maria: Advisory board fees from Eli Lilly, Nestlè, Janssen Speaker fees from AbbVie, Janssen, Eli Lilly, Ferring, Alfa Sigma, Recordati, Noòs, and Pfizer Mucherino, Caterina: Takeda, Pfizer, Alfasigma, Galapagos, Johnson & Johnson, Miranda, Agnese: No conflict of interest Vespere, Giuliana: none Imperatore, Nicola: None to declare Capone, Pietro: No conflict of interest Patturelli, Marta: No conflict of interest Gravina, Antonietta Gerarda: Gravina AG has conducted training activities e.g. educational continuing medical activities (ECM), preceptorship for Pfizer, Galapagos Biopharma, and AbbVie. Pellegrini, Lucienne: No conflict of interest Gentile, Ivan: No conflict of interest
Castiglione et al. (Thu,) studied this question.