Safety and immunogenicity of influenza A(H3N2) component vaccine in juvenile systemic lupus erythematosus

Abstract Introduction Seasonal influenza A (H3N2) virus is an important cause of morbidity and mortality in the last 50 years in population that is greater than the impact of H1N1. Data assessing immunogenicity and safety of this virus component in juvenile systemic lupus erythematosus (JSLE) is lacking in the literature. Objective To evaluate short-term immunogenicity and safety of influenza A/Singapore (H3N2) vaccine in JSLE. Methods 24 consecutive JSLE patients and 29 healthy controls (HC) were vaccinated with influenza A/Singapore/INFIMH-16-0019/2016(H3N2)-like virus. Influenza A (H3N2) seroprotection (SP), seroconversion (SC), geometric mean titers (GMT), factor increase in GMT (FI-GMT) titers were assessed before and 4 weeks post-vaccination. Disease activity, therapies and adverse events (AE) were also evaluated. Results JSLE patients and controls were comparable in current age [14.5 (10.1–18.3) vs. 14 (9–18.4) years, p = 0.448] and female sex [21 (87.5%) vs. 19 (65.5%), p = 0.108]. Before vaccination, JSLE and HC had comparable SP rates [22 (91.7%) vs. 25 (86.2%), p = 0.678] and GMT titers [102.3 (95% CI 75.0–139.4) vs. 109.6 (95% CI 68.2–176.2), p = 0.231]. At D30, JSLE and HC had similar immune response, since no differences were observed in SP [24 (100%) vs. 28 (96.6%), p = 1.000)], SC [4 (16.7%) vs. 9 (31.0%), p = 0.338), GMT [162.3 (132.9–198.3) vs. 208.1 (150.5–287.8), p = 0.143] and factor increase in GMT [1.6 (1.2–2.1) vs. 1.9 (1.4–2.5), p = 0.574]. SLEDAI-2K scores [2 (0–17) vs. 2 (0–17), p = 0.765] and therapies remained stable throughout the study. Further analysis of possible factors influencing vaccine immune response among JSLE patients demonstrated similar GMT between patients with SLEDAI  0.05). Conclusion This is the first study that identified adequate immune protection against H3N2-influenza strain with additional vaccine-induced increment of immune response and an adequate safety profile in JSLE. ( www.clinicaltrials.gov , NCT03540823)