POS0193 LONG-TERM IMMUNOGENICITY OF A LIVE ATTENUATED HERPES ZOSTER VACCINE IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS: EXTENDED OBSERVATION FROM A RANDOMIZED CONTROLLED TRIAL
Authors: S. M. Tse, C. C. Mok, K. L. Chan
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Objectives:</h3> To study the 5-year immunogenicity of a live attenuated herpes zoster (HZ) vaccine in patients with systemic lupus erythematosus (SLE). <h3>Methods:</h3> This is an extended observational study of the immunogenicity of a live attenuated HZ vaccine (Zostavax) in patients with stable SLE (SLEDAI &lt;6 and stable immunosuppressive treatment for ≥6 months). Patients who participated in a placebo (PBO)-controlled randomized controlled trial (RCT) of Zostavax were recruited for reassessment of humoral and cell-mediated response to HZ at 5 years after study entry. Anti-VZV IgG reactivity was performed by an enzyme-linked fluorescence assay, whereas cell-mediated response was assessed by a VZV-stimulated IFN-γ enzyme-linked ELISPOT assay. <h3>Results:</h3> Of the 90 patients participated in the RCT, 70 patients consented for this extension study (32 treated with vaccine; 38 treated with PBO; age 51.9±15.5 vs 50.0±13.2 years; p=0.59; 91% vs 97% women; p=0.33). Baseline clinical parameters were similar between the two groups. All completed the repeat tests for humoral response but only 44 patients were available for the cell-mediated response evaluation at year 5. The change in anti-VZV IgG reactivity from baseline to year 5 was +11.1% in the vaccine (p=0.19) and -12.0% in the placebo (p=0.01) group. The anti-VZV IgG reactivity at year 5 was significantly higher in vaccinated than PBO-treated patients, after adjustment for baseline values (3.61±1.56 vs 2.94±1.03; p=0.01). The proportion of patient who had a drop in anti-VZV IgG by ≥10% at year 5 were significantly lower in vaccinated (15.6%) than PBO-treated (47.4%) patients (p=0.006). On the other hand, the number of IFN-γ secreting T-cell spots increased in vaccinated patients at year 5 (N=26) (+140%; p=0.06) but decreased in PBO-treated patients (N=18) (-34.1%; p=0.30). The T-cell spots number at year 5 was higher in vaccine- than PBO-treated patients after adjustment for baseline values (57.9±71.6 vs 26.3±26.2; p=0.08). The proportion of patients who had a reduction in T-cell spots number by ≥10% at year 5 was significantly lower in vaccination (30.8%) than PBO-treated (61.1%) patients (p=0.046). Among patients vaccinated with Zostavax, there was a trend of higher cumulative prednisolone used in the extension period in those who had reduction in T-cell spots number by ≥10% than those who did not (4.29±3.71 vs 2.34±3.44 grams; p=0.23). One vaccinated patient (3.1%) and three PBO-treated patients (7.9%) experienced HZ infection, but the difference was not statistically significant (p=0.62). <h3>Conclusion:</h3> Immunogenicity of Zostavax in patients with stable SLE is largely retained at 5 years post-vaccination. Patients who receive higher cumulative prednisolone doses are more prone to have a reduction in humoral and cell-mediated response to the live attenuated vaccine. <h3>REFERENCES:</h3> <b>NIL.</b> <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> <b>None declared.</b>