POS0119 VACCINATION RATE AND PROTECTION AGAINST VARICELLA AND ZOSTER THROUGH VZV VACCINATION IN JUVENILE IDIOPATHIC ARTHRITIS PATIENTS
Authors: G. Horneff, A. Maurer
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Vaccinations are among the most effective and cost-effective preventions in medicine. In Germany, VZV vaccination was generally recommended in 2004. <h3>Objectives:</h3> Evidence of vaccine safety and efficacy in children with rheumatic diseases is steadily increasing but vaccination status in children on immunosuppressive therapy remains questionable. <h3>Methods:</h3> The database of the BiKeR-registry was analysed for the occurrence of primary varicella and zoster in JIA patients with and without VZV vaccination. Vaccine protection was further related to age, gender, disease activity, immunosuppressive therapy and infection and vaccination status before inclusion into BiKeR. <h3>Results:</h3> The cohort analysed consists of 5033 JIA patients, 1643 (32.6%) boys and 3390 (67.4%) girls recruited up to 14/10/2021. The mean age at inclusion in the registry was 11.1 ± 4.7 years in boys and 10.9 ± 4.8 years in girls, the average duration of observation was 3.8±3.6 years. Rheumatoid factor-negative polyarthritis was found most frequently with a total of 1613 patients (32.1%), followed by extended oligoarthritis with 952 (18.9%) and enthesitis-associated arthritis with 801 JIA patients (15.9%). The varicella infection rates that occurred before inclusion in the BiKeR register was 100% in birth year cohort until 1996 while it stepwise decreased to 0 in the most recent years. Yearly vaccination rate increased stepwise from 2005 to 2021 to about 66%. In total 1389 (27.6%) JIA patients have been vaccinated but 3644 (72.4%) have not. A primary varicella infection was reported as an adverse event (AE) in 32 children (0.6%; incidence 166.9/ 100,000 person-years). 15 (0.48%) varicella infections occurred despite documented vaccination. The median duration of varicella was 11 days in non-immunized, 9 days (p=0.219) in vaccinated children. The course was mild in 40% and moderate in 60% in vaccinated children while unvaccinated in 82% had a mild and in 18% a moderate course. Permanent damage was not documented. 7 herpes zoster cases occurred in a total of 1335 (0.5%) vaccinated JIA patients and 37 zoster in 3698 1713 (1.2%) patients after varicella wild virus infection and 2 herpes zoster in cases with both, VZV infection and vaccination. The mean and median observation period of 3.65±2.9 (median 2.9; IQR 1.26-5.19) for the group of vaccinated persons was comparable to the group of persons previously infected with VZV (3.7 ± 3.0 years, median 3.1; IQR 1.2-5.4). The risk of herpes zoster is thus significantly increased with wild virus infection (RR 2.6 95% CI 1.1-6.0; p=0.028, Wald test), and there is a significantly lower risk of zoster after vaccination (RR 0.39 [0.17-0.90; p&lt;0.05]. In children with psoriatic arthritis, H. zoster (7; 1.9%) occurred 2.3 times more frequently (p &lt; 0.001) and in rheumatoid factor-positive polyarthritis (7; 2.3%) 2.2 times more frequently (p &gt; 0.001) compared to the other JIA categories. Compared to patients treated with methotrexate (6 zoster, 0.34%) only, those exposed to TNF inhibitors ± methotrexate (38; 0.9%) had a higher zoster rate (p=0.033). Children who developed herpes zoster during the course of therapy (N=40) had a significantly higher mean JADAS10 of 17.4 ± 6.9 at the start of therapy (on inclusion in the registry) than children who did not develop H. zoster (14.75 ± 7.36, p = 0.012). <h3>Conclusion:</h3> The VZV vaccination status in JIA patients is unsatisfactory. Zoster occurs significantly more frequently after a wild virus infection than after vaccination demonstrating it's efficacy. In addition, JIA patients with higher JADAS at the start of therapy, those with rheumatoid factor-positive polyarthritis or psoriatic arthritis with TNF inhibitors had a higher risk of zoster. Vaccination status should be checked and completed before treatment. <h3>REFERENCES:</h3> <b>NIL.</b> <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> <b>None declared.</b>