Abstract
INTRODUCTION: Over 95% of healthy subjects develop anti-COVID IgG antibodies after receiving two doses of BNT162b2 COVID-19 vaccine. In comparison, 20%-30% of SLE patients do not seroconvert following 1-2 doses of COVID vaccines, potentially due to immunosuppression. The aim of this study was to assess immunogenicity and safety of BNT vaccine in SLE patients treated with Belimumab and especially the yield of a booster third dose in this population. METHODS: SLE patients treated with Belimumab in the Sheba Medical Center, Israel, were included in this study. All were recommended to receive the BNT vaccine according to national guidelines; and were advised to perform serologic tests after receiving second and third doses. Clinical data included demographics, SLE treatments, adverse effects to vaccines and SLEDAI scores performed 2 weeks before vaccinations and 6-12 weeks after receiving the second or third dose of the vaccine. RESULTS: Our cohort included 17 patients, 14 (82.35%) females, median age 50 ± 14.2 years, and disease duration 12 ± 10.57 years. Belimumab therapy was given for a mean of 6 ± 2.5 years. Of them, 15/17 patients received 3-doses of BNT vaccine. Serologic assessment was performed for 10 patients, 7/10(70%) became seropositive following the second dose, while 2/3 patients seroconverted only after the third dose. Vaccinations were well tolerated with minimal adverse events and no disease flares. SLEDAI scores before and after vaccinations were 4 ± 3.8 and 4 ± 2.7 (p = 0.69), respectively. CONCLUSIONS: Immunization with the BNT vaccine is efficacious and safe for SLE patients treated with Belimumab. Following the third dose of vaccine, immunogenicity among SLE patients mounted to 90%, thereby approximating the general healthy population. No SLE disease flares and/or significant adverse events were noted in our cohort. Assessment of seroconversion and consideration of subsequent boosters of COVID-vaccine should be considered in this group of patients.