Abstract
Objective: To clarify the safety and influence of the recombinant zoster vaccine（RZV）on disease activity（DA）in Japanese patients with rheumatic diseases.
Patients: We administered RZV to 67 patients（male, n=11; female, n=56）with rheumatic diseases（including 60 rheumatoid arthritis [RA] patients）. The mean age（n=67）and observational period after the second dose（n=64）were 73.5 ± 10.2 years old and 12.6 ± 5.7 months, respectively.
Methods: Adverse events（AEs）, the occurrence of herpes zoster（HZ）, and changes in disease activity were analyzed. Patients using Janus kinase inhibitors（JAKis）with and without RZV were compared retrospectively.
Results: After the first dose, an 82-year-old female RA patient died of pneumonia. Twelve（17.9%）and six（9.4%）AEs occurred after the first dose and second dose, respectively, but most were mild. No patients developed HZ after two doses of RZV. The DA in 57 RA patients was ameliorated at 6 months after RZV due to treatment intensification. The DA of 17 RA patients without treatment change before COVID-19 vaccination was unchanged. Patients who used JAKis without RZV were significantly younger and had a shorter disease duration than those who used JAKis with RZV. Eight of 54 patients（14.8%）who did not receive RZV developed HZ, while none who received RZV developed HZ.
Conclusion: RZV was relatively safe, and no patients developed HZ, although the observational period was only approximately one year. RZV did not worsen DA in Japanese patients with rheumatic diseases.
