POS0258 SAFETY AND IMMUNOGENICITY OF BNT162b2 mRNA COVID-19 VACCINE AMONG ADOLESCENTS WITH RHEUMATIC DISEASES TREATED WITH IMMUNOMODULATORY MEDICATIONS

Abstract

Background: Adolescents with juvenile-onset autoimmune infammatory rheumatic diseases (AIIRD) could be at risk for disease fare secondary to SARS-CoV-2 infection or to withholding anti-infammatory therapy. While vaccination can protect against COVID-19, safety and immunogenicity data regarding anti-SARS-CoV-2 vaccines among adolescents with AIIRD are limited. Objectives: This international, prospective, multicentre study evaluated the safety and immunogenicity of the BNT162b2 anti-SARS-CoV-2 vaccine among adolescents and young adults with juvenile-onset AIIRD, 80% of whom are on chronic immunomodulatory therapy. Methods: Vaccine side effects, disease activity, and short-term efficacy were evaluated after 3 months in 91 patients. Anti-spike S1/S2 IgG antibody levels were evaluated in 37 patients and 22 controls, 2-9 weeks after the second dose. Results: Ninety-one patients and 40 healthy controls were included. Safety pro-file was good, with 96.7% (n=88) of patients reporting mild or no side-effects, and no change in disease activity. However, 3 patients had transient acute symptoms: 2 following the frst vaccination (renal failure and pulmonary haemorrhage) and 1 following the second dose (mild lupus fare vs. viral infection). Seropositivity rate was 97.3% in the AIIRD group compared with 100% among controls. However, anti-S1/S2 antibody titres were signifcantly lower in the AIIRD group compared with controls (242±136.4 vs. 387.8±57.3 BAU/ml, respectively; p<0.0001). No cases of COVID-19 were documented during the 3-month follow-up. Conclusion: Vaccination of juvenile-onset AIIRD patients demonstrated good short-term safety and efficacy, high seropositivity rate, but lower anti-S1/S2 antibody titres compared to healthy controls. These results should encourage vaccination of adolescents with juvenile-onset AIIRD, even while on immunomodulation.