tetano
Editor, Senior Moderator
Clin Exp Pediatr
. 2026 Sep 30.
doi: 10.3345/cep.2026.01298. Online ahead of print.
Anthie Damianaki 1 , Antonios Marmarinos 2 , Margaritis Avgeris 2 , Dimitrios Gourgiotis 2 , Elpis-Athina Vlachopapadopoulou 3 , Marietta Charakida 4 , Maria Tsolia 4 , Lydia Kossiva 4
Affiliations Expand
Background: Obesity causes chronic inflammation and metabolic dysregulation of the immune response and increases an individual's susceptibility to severe infection.
Purpose: This study aimed to evaluate the effect of an increased body mass index (BMI), obesity-associated biomarkers, and habitual factors on immune responses following BNT162b2 vaccination in a pediatric population over a 6-month period.
Methods: In this prospective, single-center cohort study, the participants received a 2-dose regimen of the BNT16 2b2 mRNA vaccine. Anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin G (IgG) and neutralizing antibody (Ab) levels were measured before vaccination (T0), 14 days after vaccination (T1), and 6 months after the second dose (T2). Baseline anthropometric and biochemical assessments including BMI measurements were performed at T0. Lifestyle characteristics were evaluated using a standardized questionnaire administered at baseline.
Results: T2 SARS-CoV-2 neutralizing Ab levels were significantly lower in overweight or obese participants (P= 0.02). Among the other biochemical markers, hepcidin, and leptin levels were significantly correlated with BMI (P= 0.004 and P<0.001, respectively). The main biochemical parameters that were inversely correlated with T1 IgG and neutralizing titers were uric acid (P=0.007, P<0.001), fasting serum glucose-to-plasma insulin ratio (P=0.02 and P=0.02), and hepcidin (P=0.01 and P=0.01). Passive smoking was associated with lower T2 IgG titers (P=0.04). Higher uric acid levels and a lower KIDMED index were associated with reduced T2 SARS-CoV-2 neutralizingtiters (P=0.005 and P=0.02, respectively). Reactogenicity was significantly correlated with BMI and age (P=0.03 and P= 0.02, respectively), whereas higher hepcidin and uric acid levels were associated with the presence of local and systemic adverse effects, respectively (P=0.008 and P= 0.02, respectively).
Conclusion: Our findings suggest that obesity-related environmental and behavioral factors may be associated with humoral immune responses during 6 months of follow-up.
Keywords: BNT162b2 vaccine; Hepcidin; Mediterranean diet; Obesity; Secondhand smoking.
. 2026 Sep 30.
doi: 10.3345/cep.2026.01298. Online ahead of print.
Hepcidin and other obesity-related factors affecting BNT162b2 response in children and adolescents over a 6-month period
Anthie Damianaki 1 , Antonios Marmarinos 2 , Margaritis Avgeris 2 , Dimitrios Gourgiotis 2 , Elpis-Athina Vlachopapadopoulou 3 , Marietta Charakida 4 , Maria Tsolia 4 , Lydia Kossiva 4
Affiliations Expand
- PMID: 42822528
- DOI: 10.3345/cep.2026.01298
Abstract
Background: Obesity causes chronic inflammation and metabolic dysregulation of the immune response and increases an individual's susceptibility to severe infection.
Purpose: This study aimed to evaluate the effect of an increased body mass index (BMI), obesity-associated biomarkers, and habitual factors on immune responses following BNT162b2 vaccination in a pediatric population over a 6-month period.
Methods: In this prospective, single-center cohort study, the participants received a 2-dose regimen of the BNT16 2b2 mRNA vaccine. Anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin G (IgG) and neutralizing antibody (Ab) levels were measured before vaccination (T0), 14 days after vaccination (T1), and 6 months after the second dose (T2). Baseline anthropometric and biochemical assessments including BMI measurements were performed at T0. Lifestyle characteristics were evaluated using a standardized questionnaire administered at baseline.
Results: T2 SARS-CoV-2 neutralizing Ab levels were significantly lower in overweight or obese participants (P= 0.02). Among the other biochemical markers, hepcidin, and leptin levels were significantly correlated with BMI (P= 0.004 and P<0.001, respectively). The main biochemical parameters that were inversely correlated with T1 IgG and neutralizing titers were uric acid (P=0.007, P<0.001), fasting serum glucose-to-plasma insulin ratio (P=0.02 and P=0.02), and hepcidin (P=0.01 and P=0.01). Passive smoking was associated with lower T2 IgG titers (P=0.04). Higher uric acid levels and a lower KIDMED index were associated with reduced T2 SARS-CoV-2 neutralizingtiters (P=0.005 and P=0.02, respectively). Reactogenicity was significantly correlated with BMI and age (P=0.03 and P= 0.02, respectively), whereas higher hepcidin and uric acid levels were associated with the presence of local and systemic adverse effects, respectively (P=0.008 and P= 0.02, respectively).
Conclusion: Our findings suggest that obesity-related environmental and behavioral factors may be associated with humoral immune responses during 6 months of follow-up.
Keywords: BNT162b2 vaccine; Hepcidin; Mediterranean diet; Obesity; Secondhand smoking.