Humoral and cellular immune response to mRNA SARS-CoV-2 BNT162b2 vaccine in adolescents with rheumatic diseases.

BACKGROUND: Data about safety and efficacy of the mRNA SARS-CoV-2 vaccine in adolescents with rheumatic diseases (RD) is scarce and whether these patients generate a sufficient immune response to the vaccine remains an outstanding question. OBJECTIVE: To evaluate safety and humoral and cellular immunity of the BNT162b2 vaccine in adolescents 12 to 18 years with RD and immunosuppressive treatment compared with a healthy control group. METHODS: Adolescents from 12 to 18 years with RD followed at Hospital La Paz in Madrid (n = 40) receiving the BNT162b2 mRNA vaccination were assessed 3 weeks after complete vaccination. Healthy adolescents served as controls (n = 24). Humoral response was measured by IgG antiSpike antibodies, and cellular response by the quantity of IFN-γ and IL-2 present in whole blood stimulated with SARS-CoV-2 Spike and M proteins. RESULTS: There were no differences in spike-specific humoral or cellular response between groups (median IFN-γ response to S specific protein; 528.80 pg/ml in controls vs. 398.44 in RD patients, p 0.78, and median IL-2 response in controls: 635.68 pg/ml vs. 497.30 in RD patients, p 0.22. The most frequent diagnosis was juvenile idiopathic arthritis (26/40, 65%) followed by Lupus (6/40, 15%). 60% of cases (23/40) received TNF inhibitors and 35% (14/40) methotrexate. 40% of patients (26/64) had previous SARS-CoV-2 infection, 9 in the control group and 17 in the RD patients without differences. Of note, 70% of infections were asymptomatic. A higher IFN-γ production was found in COVID-19 recovered individuals than in naive subjects in both groups (controls: median 859 pg/ml in recovered patients vs. 450 in naïve p 0.017, and RD patients: 850 in recovered vs. 278 in naïve p 0.024). No serious adverse events or flares were reported following vaccination. CONCLUSIONS: We conclude that standard of care treatment for adolescents with RD including TNF inhibitors and methotrexate did not affect the humoral and the cellular immunity to BNT162b2 mRNA vaccination compared to a healthy control group. The previous contact with SARS-CoV-2 was the most relevant factor in the immune response.

Clinical course and seroprevalence of COVID-19 in children with rheumatic diseases-cross-sectional study from a reference centre in Spain.

SARS-CoV-2 infections in children are frequently asymptomatic or mild and can go unnoticed. This study aimed to describe the seroprevalence and clinical course of SARS-CoV-2 in a cohort of children with rheumatic diseases in a real-life setting and assess possible risk factors. A cross-sectional study was performed in a paediatric rheumatology unit (September 2020 to February 2021). At inclusion, a specific questionnaire was completed and SARS-CoV-2 serology was performed. Demographics, treatment and disease activity of patients with and without laboratory-confirmed SARS-CoV-2 infection were compared. A total of 105 children were included. SARS-CoV-2 infection was demonstrated in 27 patients (25.7%). The mean age was 11.8 years, and most patients were females (72.4%). The most frequent underlying condition was juvenile idiopathic arthritis (70.3%; 19/27). Patients received immunosuppressive treatment in 78% of cases (21/27). Overall, 44.4% (12/27) of infected patients were asymptomatic. A total of 66.7% (18/27) of patients did not require medical assistance. Three patients required hospital admission because of COVID-19. Children with confirmed SARS-CoV-2 infection were less frequently in remission (52% vs 72%; p 0.014). Moderate disease activity and treatment with oral corticosteroids were associated with higher risk for SARS-CoV-2 (OR 5.05; CI 95%: 1.56-16.3 and OR 4.2; CI 95%: 1.26-13.9, respectively). In a cohort of Spanish paediatric patients with rheumatic diseases, clinical course of COVID-19 was mild, with more than one third of asymptomatic cases. Higher disease activity and oral corticosteroids appear to be risk factors for SARS-CoV-2 infection. Key Points • We aimed to investigate the seroprevalence of SARS-CoV-2 infection in a cohort of Spanish paediatric patients with RD, testing both symptomatic and asymptomatic patients. We also compared treatment and disease activity of patients with and without laboratory-confirmed SARS-CoV-2 infection. • In our cohort of 105 paediatric patients with rheumatic diseases, the clinical course of COVID-19 was mild and 44% of cases were asymptomatic. Three cases required hospital admission with no complications. Seroprevalence was 20%. • No association was found between disease activity or treatment with corticosteroids and symptomatic or asymptomatic infection. Higher disease activity and treatment with oral corticosteroids appeared to be risk factors for laboratory-confirmed SARS-CoV-2 infection.