Global burden of vaccine-associated rheumatic diseases and their related vaccines, 1967-2023: A comprehensive analysis of the international pharmacovigilance database.

Vaccine-associated rheumatic diseases are rare but one of the most feared adverse drug reactions (ADRs). However, this topic has been investigated less with large-scale data in the literature. With the rapid progress in the development and approval of vaccines during the pandemic, public concerns regarding their safety have been raised. To assess the global and regional burden, long-term trends, and potential risk factors of vaccines-associated six types of rheumatic diseases (ankylosing spondylitis [AS], polymyalgia rheumatica [PMR], rheumatoid arthritis [RA], Sjögren's syndrome, Systemic lupus erythematosus [SLE], Systemic scleroderma), this study conducted disproportionality analysis based on the reports from the World Health Organization International Pharmacovigilance Database documented between 1967 and 2023 (n for total reports = 131 255 418) across 156 countries and territories. We estimated the reporting odds ratio (ROR) and information component (IC) to determine the disproportionality signal for rheumatic diseases. Of 198 046 reports of all-cause rheumatic diseases, 14 703 reports of vaccine-associated rheumatic diseases were identified. While the reporting counts have gradually increased over time globally, we observed a dramatic increase in reporting counts after 2020, potentially due to a large portion of reports of COVID-19 mRNA vaccine-associated rheumatic diseases. The disproportionality signal for rheumatic diseases was most pronounced in HBV vaccines (ROR, 4.11; IC025, 1.90), followed by COVID-19 mRNA (ROR, 2.79; IC025, 1.25), anthrax (ROR, 2.52; IC025, 0.76), papillomavirus (ROR, 2.16; IC025, 0.95), encephalitis (ROR, 2.01; IC025, 0.58), typhoid (ROR, 1.91; IC025, 0.44), influenza (ROR, 1.49; IC025, 0.46), and HAV vaccines (ROR, 1.41; IC025, 0.20). From age- and sex-specific perspective, young females and old males are likely to have vaccine-associated rheumatic disease reports. Furthermore, overall vaccines showed a disproportionality signal for PMR (IC025, 3.13) and Sjögren's syndrome (IC025, 0.70), systemic scleroderma (IC025, 0.64), specifically while the COVID-19 mRNA vaccines are associated with all six types of diseases. Although multiple vaccines are associated with rheumatic disease reports, healthcare providers should be aware of the potential of autoimmune manifestations following vaccination, particularly the COVID-19 mRNA and HBV vaccines, and take into account for risk factors associated with these ADRs. Most ADRs exhibited an average time to onset of 11 days, underscoring the significance of monitoring and timely management by clinicians.

Safety of biologic agents for the management of rheumatic diseases during pregnancy.

PURPOSE OF REVIEW: To discuss the current understanding regarding the use of biologic therapeutics in pregnancy. RECENT FINDINGS: Our understanding of the mechanisms underlying the potential fetal and infant exposure to biologics as well as a growing body of empirical evidence from real world use of biologics in pregnancy have demonstrated that biologics are generally compatible preconception and during pregnancy. Long-term effects of exposure to biologic agents in utero are not known, but will be uncovered in time. Biosimilars, which are becoming more popular, may not always share the same safety profiles as their originators. SUMMARY: Biologics have revolutionized the management of rheumatologic disease and ushered in a new era of clinical remission among patients. These agents, developed and introduced into clinical use at the beginning of the new millennium, are very potent, yet their efficacy in treating disease often in reproductive aged women, raises questions regarding their safety during pregnancy. These therapeutics can cause immunosuppression and can inhibit immunologic circuits that are not only involved in disease pathophysiology but hypothetically could impact the development of the fetal immune system. Reassuringly, biologics, typically antibodies or antibody-based proteins, are introduced to the fetus via the typical route of transplacental antibody transfer, and thus only begin to be transferred in appreciable amounts in the second trimester (after organogenesis). From theoretic and empirical standpoints, biologic use during pregnancy appears well tolerated for fetal development and to not substantially affect infant immune development.

Time to talk to adults with rheumatic diseases about herpes zoster vaccination.

The 2019 European Alliance of Associations for Rheumatology (EULAR) recommendations on herpes zoster vaccination for adult patients with rheumatic immune-mediated inflammatory diseases stated that these patients are at increased risk of herpes zoster compared with the general population. However, these recommendations lack clarity and specificity and are cautiously phrased, which might cause physicians to underestimate the importance of herpes zoster vaccination for these patients, potentially resulting in suboptimal protection. Since the formulation of the 2019 EULAR guidelines, new data on herpes zoster in patients with immune-mediated inflammatory diseases have been published. Moreover, a recombinant herpes zoster vaccine (Shingrix) has become available that can be given to these patients in a more accessible manner than the original live-attenuated vaccine (Zostavax). Here, we evaluate existing evidence on risk factors for herpes zoster and the safety and efficacy of the recombinant vaccine in patients with rheumatic immune-mediated inflammatory diseases and discuss the necessity of herpes zoster vaccination for these patients.

[Therapeutic antibodies in rheumatology]. / Therapeutische Antikörper in der Rheumatologie.

Emil von Behring's serum therapy for diphtheria was the first therapeutic use of antibodies. More than 100 years later, a new era in the treatment of rheumatic diseases began in 1998 with the approval of infliximab, an antibody directed against tumor necrosis factor alpha (TNF alpha). The special feature of antibody therapy is the ability to bind and neutralize antigens in a highly specific manner. In addition, target cells can be eliminated by activation of the immune system. These properties of the immune system are exploited in rheumatology to eliminate inflammatory cytokines or antibody-producing B lymphocytes. The tolerability is usually good but potential side effects, such as reactivation of tuberculosis with anti-TNF alpha treatment must be considered. Currently, 20 different antibodies and fusion proteins have been approved in Germany for the treatment of various inflammatory rheumatic diseases. Biosimilars can contribute to a price reduction after the patent protection expires. Many additional target antigens are being investigated and further structural innovations (e.g., bispecific antibodies, nanobodies or coupling with small molecules) are being developed.

Cancer risk with biologic and targeted synthetic DMARDs in patients with rheumatic diseases and previous malignancies: Results from the BIOBADASER register.

OBJECTIVE: to investigate the occurrence and relative risk of incident malignancy in patients with rheumatic diseases and previous malignancies treated with biologic and targeted synthetic DMARDs (b/tsDMARDs). METHODS: Cohort study of patients included in BIOBADASER 3.0 up to 2021, treated with b/tsDMARDs and history of a previous malignancy. Incident cancer was defined as any cancer (new primary, local recurrence or metastases) during the drug exposure. Incidence rate ratios of cancer per 1,000 patients-year (PY) and 95 % confidence interval (CI) were estimated. Rates of incident cancer in tsDMARDs and other bDMARDs versus TNFi were compared. RESULTS: A total of 352 patients from over 9,129 patients recorded in BIOBADASER 3.0 had a history of a previous malignancy. Overall, there were 47 incident malignancies (28 solid cancers, 18 non-melanoma skin cancers and 1 melanoma). The overall rate of incident malignancy was 47.4 (95 % CI 35.6-63.1) events/1,000 PY, ranging between 24.5 events/1000 PY in the anti-CD20 group to 93 events/1000 PY in the anti-CTLA-4 group. We did not find differences in the adjusted rate of incident cancer in patients exposed to JAKi [0.5 (95 % CI 0.2-1.7)], anti-CD20 [0.4(95 % CI 0.1-1)], or anti-IL6 [1.1(95 % CI 0.5-2.4)], anti-CTLA-4 [1.5 (95 % CI 0.7-3.1) or anti-IL17 [0.7 (95 % CI 0.2-2.4) versus TNFi therapy. CONCLUSIONS: We did not find differences in the risk of incident cancer in patients with rheumatic diseases and a previous malignancy between TNFi and other b/tsDMARDs. While incident cancers in our cohort were limited, our data is reassuring, awaiting validation in future studies.

Budget impact analysis and treatment availability with biosimilar TNF inhibitors in rheumatic diseases in Poland: real-world evidence using a nationwide database.

OBJECTIVES: Although several years have passed since biologic disease modifying antirheumatic drugs were introduced to the market, considerable disparities in access still remain. Tumour necrosis factor inhibitors (TNFi) have proven to be highly effective and safe for treating patients with rheumatic musculoskeletal diseases (RMDs). The emergence of biosimilars is promising for cost reduction and more equitable, widespread access. METHODS: A retrospective budget impact analysis based on final drug prices was conducted using 12 687 treatment courses for infliximab, etanercept and adalimumab. Estimated and real-life savings for public payer were calculated from an 8-year perspective of TNFi use. Data on the treatment cost and on the evolution in the number of patients treated was provided. RESULTS: From a public payer perspective, the estimated total savings amount to over €243 million for TNFi, with over €166 million attributed to treatment cost reduction in RMDs. Real-life savings were calculated as €133 million and €107 million, respectively. The rheumatology sector generated between 68% and 92% of total savings across models, depending on the adopted scenario. The overall decrease in mean annual cost of treatment ranged between 75% and 89% in the study frame. If all budget savings were spent on reimbursement of additional TNFi, a hypothetical total of almost 45 000 patients with RMDs could be treated in 2021. CONCLUSIONS: This is the first nation-level analysis that shows estimated and real-life direct cost-savings for TNFi biosimilars. Transparent criteria for reinvesting savings should be developed on both a local and an international levels.

The Emerging Safety Profile of JAK Inhibitors in Rheumatic Diseases.

Janus kinase inhibitor (JAKi) medications are small-molecule drugs that affect intracellular signal transduction. They are highly effective oral medications that have been approved for the treatment of various rheumatic diseases, with rheumatoid arthritis being a key example of an autoimmune rheumatic disease. JAKi are oral-route medications that are alternatives to injectable biologic therapies, launched in the late 1990s. While most safety concerns with JAKi are similar to the biologics, there are many differences. New data on comparative safety of JAKi versus tumor necrosis factor inhibitors (TNFi) were recently published that led to new black box warnings by the US Food and Drug Administration (FDA) about cardiovascular and cancer risks and a label change for JAKi. This review summarizes the current published data with regards to the safety of JAKi, focused on rheumatic diseases. Specifically, any risk differences between agents or across different indications are discussed, as well as the risk factors for these adverse outcomes.

Risk-Benefit Analysis of Primary Prophylaxis Against Pneumocystis Jirovecii Pneumonia in Patients With Rheumatic Diseases Receiving Rituximab.

OBJECTIVE: To identify a specific population of patients with rheumatic diseases receiving rituximab treatment for whom the benefit from primary prophylaxis against Pneumocystis jirovecii pneumonia (PJP) outweighs the risk of adverse events (AEs). METHODS: This study included 818 patients treated with rituximab for rheumatic diseases, among whom 419 received prophylactic trimethoprim/sulfamethoxazole (TMP/SMX) with rituximab, while the remainder did not. Differences in 1-year PJP incidence between the groups were estimated using Cox proportional hazards regression. Risk-benefit assessment was performed in subgroups stratified according to risk factors based on the number needed to treat (NNT) to prevent 1 case of PJP and the number needed to harm (NNH) due to severe AEs. Inverse probability of treatment weighting was applied to minimize the confounding by indication. RESULTS: During the 663.1 person-years, there were 11 PJP cases, with a mortality rate of 63.6%. Concomitant use of high-dose glucocorticoids (≥30 mg/day of prednisone or equivalent during 4 weeks after rituximab administration) was the most important risk factor. The PJP incidence (per 100 person-years) was 7.93 (95% confidence interval [95% CI] 2.91-17.25) in the subgroup receiving high-dose glucocorticoids compared with 0.40 (95% CI 0.01-2.25) in the subgroup without high-dose glucocorticoid use. Although prophylactic TMP/SMX significantly reduced the overall PJP incidence (HR 0.11 [95% CI 0.03-0.43]), the NNT to prevent 1 case of PJP (146) was higher than the NNH (86). In contrast, the NNT fell to 20 (95% CI 10.7-65.7) in patients receiving concomitant high-dose glucocorticoids. CONCLUSION: The benefit associated with primary PJP prophylaxis outweighs the risk of severe AEs in patients with rheumatic diseases receiving rituximab and concomitant high-dose glucocorticoid treatment.

COVID-19 disease frequency, risk factors, and re-infection rates in patients with autoimmune rheumatic disease receiving rituximab.

INTRODUCTION: Rituximab, which is used in autoimmune rheumatic diseases (ARD), can cause both an increased risk of development of COVID-19 disease and re-infection due to its potent and long-acting immunosuppression. So, we aimed to evaluate the frequency, risk factors and re-infection rates of COVID-19 in ARD patients receiving rituximab. METHODS: A single-center retrospective study was performed with patients receiving rituximab for ARD in 12 months before the onset of COVID-19 in Turkey. The data regarding severe acute respiratory syndrome-coronavirus 2 reverse transcription polymerized chain reaction (RT-PCR) test, clinical, laboratory, and mortality data of all patients were collected from medical records. Logistic regression analysis was used for predictors of COVID-19 disease. COVID-19 re-infection was defined as RT-PCR positivity and recurrence of acute COVID-19 symptoms after at least 1 negative RT-PCR in patients with clinical improvement. RESULTS: Ninety-eight ARD patients with rituximab were evaluated and 23 (23%) of them had COVID-19. The presence of hypogammaglobulinemia increased the risk of COVID-19 disease 8-fold. COVID-19 pneumonia occurred in 13 (57%) and these patients' age was higher than those without pneumonia (59.6 ± 11.8 vs 44.9 ± 14.2 years, P = 0.013). Mortality due to COVID-19 was 13% and COVID-19 re-infection was seen in 20% of survivors. CONCLUSION: Regardless of the underlying rheumatic disease and organ involvements, hypogammaglobulinemia in ARD could be a risk factor for COVID-19 development, and advanced age could be for COVID-19 severity. Moreover, COVID-19 re-infection rates are high.

Measuring the impact of steroid therapy on health-related quality of life in patients with rheumatic diseases: international development of a glucocorticoid treatment-specific patient-reported outcome measure.

OBJECTIVES: Glucocorticoids (GCs) ('steroids') are used to treat rheumatic diseases but adverse effects are common. We aimed to explore the impact of GC therapy on health-related quality of life (HRQoL), to inform the development of a treatment-specific patient-reported outcome measure (PROM) for use in clinical trials and practice. METHODS: Semi-structured qualitative interviews were conducted with patients from the UK, USA and Australia, treated for a rheumatic condition with GCs in the last 2 years. Purposive sampling was used to select participants with a range of demographic and disease features. An initial conceptual framework informed interview prompts and cues. Interviews elicited GC-related physical and psychological symptoms and salient aspects of HRQoL in relation to GC therapy. Interview data were analysed inductively to develop initial individual themes and domains. Candidate questionnaire items were developed and refined. RESULTS: Sixty semi-structured qualitative interviews were conducted (UK n = 34, USA n = 10, Australia n = 16). The mean age was 58 years; 39/60 were female; and 18 rheumatic diseases were represented. Some 126 individual themes were identified and organized into six domains: physical symptoms; psychological symptoms; psychological impact of steroids; impact of steroids on participation; impact of steroids on relationships; and benefits of steroids. Candidate questionnaire items were tested and refined by piloting with patient research partners, iterative rounds of cognitive interviews and linguistic translatability assessment, informing a draft questionnaire. CONCLUSION: We describe an international qualitative study to develop candidate items for a treatment-specific PROM for patients with rheumatic diseases. A future survey will enable the validation of a final version of the PROM.

[PHARAO study: drug treatment of inflammatory rheumatic diseases : Guideline-conform treatment with biologics follows availability of biosimilars]. / PHARAO-Studie: Arzneimittelversorgung entzündlich rheumatischer Erkrankungen : Leitliniengerechte Versorgung mit Biologika folgt Verfügbarkeit von Biosimilars.

BACKGROUND: With the introduction of tumor necrosis factor (TNF) alpha inhibitors, the treatment of inflammatory rheumatic diseases (IRD) has undergone a fundamental change. Several of the originally high-priced biologics are now accessible as lower cost biosimilars, removing a significant impediment to prescription. OBJECTIVE: The present study investigated whether the availability of biosimilars is associated with an improvement in the care of IRD. Moreover, the subjective acceptance of biosimilars by physicians and patients was investigated and compared with objectifiable parameters. MATERIAL AND METHODS: Pseudonymized claims data of the Bavarian Association of Statutory Health Insurance Physicians from 2014 to 2019 as well as a paper and pencil survey of patients and rheumatologists formed the data basis of the study. RESULTS: During the observation period, the proportion of diagnosed patients receiving drug therapy increased from 38.5% to 43.2%. Also, the care changed in terms of the prescribed agents. Conventional drug therapy declined overall and, in particular, glucocorticoid prescriptions decreased from 39.3% in 2014 to 34.3% in 2019. At the same time, the proportion of targeted treatments increased from 12.3% to 20.4%. The median duration of basic treatment before first-time bDMARD use dropped from 3.15 years in 2014 to 2.17 years in 2019. CONCLUSION: Over the observation period, in which three biosimilars entered the market, the care of patients with IRD improved both quantitatively and qualitatively. The market share of biosimilars increased in parallel with this development. With an overall high acceptance of biosimilars, the assessment of the disease course by physicians and patients indicates a slight subjectively perceived advantage of therapy with originals compared to biosimilars, which, however, is not confirmed when standardized scores are applied. A possible explanation for this might be a nocebo effect, which could be minimized by suitable communication strategies.

An update on the considerations for patients with rheumatic disease being treated with rituximab during the COVID-19 pandemic and the potential drug treatment strategies.

INTRODUCTION: Over the last two decades, rituximab has become an increasingly popular drug in the treatment of a wide range of rheumatic diseases. However, with the advent of the COVID-19 pandemic, clinicians face challenges in weighing risk against benefit in its use. AREAS COVERED: A review of existing data was performed to examine the relationship between rituximab use, morbidity and mortality from COVID-19, and vaccine efficacy in patients with rheumatic diseases, aiming to guide clinicians in continued use of the medication and consider the direction of future research. A literature review was performed through a search of the PubMed database, using the terms ((SARS-CoV-2) OR (COVID-19)) AND (rituximab) AND (rheumatic), which generated an initial 55 results, with relevant articles then selected for inclusion. EXPERT OPINION: In order to safeguard patients with an ongoing need for rituximab therapy, vaccination remains the primary concern. A target of performing booster doses 6 months after last rituximab dose is a reasonable estimate, which may be made more precise by use of B cell counts, although primary immunization should not be delayed. In those patients who remain seronegative, the use of newer antivirals and broadly neutralizing antibody infusions may help provide further safeguards.

[Recent research on tofacitinib in the treatment of pediatric rheumatic diseases]. / æ‰˜æ³•æ›¿å°¼åœ¨å„¿ç«¥é£Žæ¹¿æ€§ç–¾ç— ä¸­çš„ç ”ç©¶è¿›å±•.

Tofacitinib is a Janus kinase inhibitor and can block the Janus kinase-signal transducer and activator of transcription signal transduction pathway and reduce the production and release of a variety of cytokines. It has great potential in the treatment of various rheumatic diseases with a rapid onset of action and can reduce corticosteroid dependence and related adverse events. The therapeutic effect of tofacitinib in adult patients has been confirmed, and it has been increasingly used in pediatric patients in recent years. This article reviews the clinical application of tofacitinib in the treatment of pediatric autoimmune diseases.

Safety of COVID-19 vaccines and disease flares after vaccines in children with rheumatic disease.

OBJECTIVES: Wide spread availability of safe and effective vaccines for COVID-19 in all countries is the best hope to end the COVID-19 pandemic. However, in developing countries, the hesitancy of the society about vaccination is an important problem in terms of public health. This study aimed to investigate the acceptability and tolerability of COVID-19 vaccines in the pediatric population diagnosed with rheumatic disease, as well as the attitudes toward these vaccines. METHODS: This is an observational, cross sectional, single center study. Pediatric patients with at least one diagnosis of rheumatic disease were included in this study to investigate patient and family acceptability and safety of COVID-19 vaccines. RESULTS: A total of 228 patients with rheumatic disease were included in this study. Ninety nine (43.4%) of the patients were juvenile idiopathic arthritis. One hundred and five (46%) of the patients were using biological agent treatment for their rheumatic disease, whereas 123 (54%) of the patients were not. No serious adverse effect related to the COVID-19 vaccine were observed in any of the patients. No disease activation was observed in any of them. CONCLUSION: There are only a few studies evaluating of the safety and disease flare of COVID-19 vaccines in children with rheumatic disease. Although this study has some limitations, such as the small sample size of patients with different diagnoses, it appears that there is no increase in COVID-19 vaccination-related harms in the patients with rheumatic disease.

Diabetes-Modifying Antirheumatic Drugs: The Roles of DMARDs as Glucose-Lowering Agents.

Systemic inflammation represents a shared pathophysiological mechanism which underlies the frequent clinical associations among chronic inflammatory rheumatic diseases (CIRDs), insulin resistance, type 2 diabetes (T2D), and chronic diabetes complications, including cardiovascular disease. Therefore, targeted anti-inflammatory therapies are attractive and highly desirable interventions to concomitantly reduce rheumatic disease activity and to improve glucose control in patients with CIRDs and comorbid T2D. Therapeutic approaches targeting inflammation may also play a role in the prevention of prediabetes and diabetes in patients with CIRDs, particularly in those with traditional risk factors and/or on high-dose corticosteroid therapy. Recently, several studies have shown that different disease-modifying antirheumatic drugs (DMARDs) used for the treatment of CIRDs exert antihyperglycemic properties by virtue of their anti-inflammatory, insulin-sensitizing, and/or insulinotropic effects. In this view, DMARDs are promising drug candidates that may potentially reduce rheumatic disease activity, ameliorate glucose control, and at the same time, prevent the development of diabetes-associated cardiovascular complications and metabolic dysfunctions. In light of their substantial antidiabetic actions, some DMARDs (such as hydroxychloroquine and anakinra) could be alternatively termed "diabetes-modifying antirheumatic drugs", since they may be repurposed for co-treatment of rheumatic diseases and comorbid T2D. However, there is a need for future randomized controlled trials to confirm the beneficial metabolic and cardiovascular effects as well as the safety profile of distinct DMARDs in the long term. This narrative review aims to discuss the current knowledge about the mechanisms behind the antihyperglycemic properties exerted by a variety of DMARDs (including synthetic and biologic DMARDs) and the potential use of these agents as antidiabetic medications in clinical settings.

Humoral response and safety of BNT162b2 mRNA vaccine in children with rheumatic diseases.

OBJECTIVES: The coronavirus disease 2019 (COVID-19) vaccine represents a cornerstone in tackling the pandemic and with the approval of the BNT162b2 mRNA vaccine in December 2020, it has become a beacon of hope for people around the world, including children. This study aimed to present the data on the humoral response and safety of vaccine in a cohort of patients with paediatric rheumatic diseases receiving immunomodulatory treatments. METHODS: Forty-one children with paediatric rheumatic diseases were included and were vaccinated with the BNT162b2 mRNA vaccine (two doses of 30 µg administered 3-4 weeks apart). To assess the humoral response, IgG antibodies developed against the S1/Receptor-binding domain (RBD) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein at baseline and 3-4 weeks after the second dose were measured. The possible local and systemic side effects and disease activity scores were evaluated during the study period. RESULTS: After the second dose of vaccine, markedly elevated anti-RBD IgG titres were observed in all patients with a median titre of 20 474 AU/ml [interquartile range (IQR) 6534-36 151] with a good safety profile. The median disease duration was 4.3 (IQR 3.5-5.6) years. In the cohort, 14 (34.1%) received conventional DMARDs (cDMARDs), 16 (39%) received biologic DMARDs (bDMARDs) and 11 (26.8%) received a combined therapy (cDMARDs and bDMARDs). Patients treated with combined therapy [median 4695 (IQR 2764-26 491)] had significantly lower median titres of anti-RBD IgG than those receiving only cDMARDs. CONCLUSION: Paediatric rheumatic diseases patients receiving immunomodulatory treatments were able to mount an effective humoral response after two dose regimens of BNT162b2 mRNA vaccine safely without interrupting their current treatments.

Robust neutralizing antibody response to SARS-CoV-2 mRNA vaccination in adolescents and young adults with childhood-onset rheumatic diseases.

OBJECTIVES: Immunogenicity to the SARS-CoV-2 mRNA vaccines in adolescents and young adults (AYA) with childhood-onset rheumatic diseases (cRD) is unknown. We aimed to evaluate the humoral immunogenicity and safety of the vaccines in our AYA with cRD. METHODS: A monocentric observational study with 159 AYA (50.3% female and 70.4% Chinese). Humoral immunogenicity was assessed at 2-3 and 4-6 weeks following first and second vaccination by cPass™ SARS-CoV-2 Neutralization Antibody Assay. Inhibition signal of ≥30% defined the cut-off for positive detection of the SARS-CoV-2 neutralizing antibodies. Vaccine safety and disease activity were assessed within 6 weeks after second vaccination. RESULTS: A total of 64.9% and 99.1% of 159 patients (median age: 16.9, IQR: 14.7-19.5) mounted positive SARS-CoV-2 neutralizing responses after first and second vaccination, respectively. Most patients (89.8%) had ≥90% inhibition signal after second vaccination. Methotrexate and mycophenolate mofetil increased the risk associated with negative cPass neutralization responses following the first vaccination. Holding both medications after each vaccination did not affect immunogenicity. There was no symptomatic COVID-19 infection. Local reaction remained the most common (23.3-25.2%) adverse event, without serious complication. Two and seven patients flared following the first and second vaccination, respectively. Subgroup analyses of the 12-18-year-old cohort did not show any differences in vaccine efficacy, predictors of poor response and general safety, but higher proportion of disease flares. CONCLUSIONS: SARS-CoV-2 mRNA vaccines were efficacious after the two-dose regimen in almost all AYA with cRD without serious adverse event. The rate of disease flare observed is 4.4% after the second mRNA vaccine dose.