Details

Autor(en) / Beteiligte

• Di Chiara, Costanza
• Cantarutti, Anna
• Raffaella Petrara, Maria
• Bonfante, Francesco
• Benetti, Elisa
• Boracchini, Riccardo
• Bosa, Luca
• Carmona, Francesco
• Cosma, Chiara
• Cotugno, Nicola
• Le Prevost, Marthe
• Martini, Giorgia
• Meneghel, Alessandra
• Pagliari, Matteo
• Palma, Paolo
• Ruffoni, Elena
• Zin, Annachiara
• De Rossi, Anita
• Giaquinto, Carlo
• Donà, Daniele
• Padoan, Andrea

Titel

Stronger and durable SARS-CoV-2 immune response to mRNA vaccines in 5–11 years old children with prior COVID-19

Ist Teil von

• Vaccine, 2024-01, Vol.42 (2), p.263-270

Ort / Verlag

Netherlands: Elsevier Ltd

Erscheinungsjahr

2024

Quelle

MEDLINE

Beschreibungen/Notizen

• mRNA vaccines elicit a durable humoral response to SARS-CoV-2 in adults, whereas evidence in children is scarce. This study aimed to assess the early and long-term immune response to the mRNA vaccine in children with or without previous SARS-CoV-2 infection. In a multicentre prospective observational study, we profiled the immune response to the Pfizer BioNTech (BNT162b2) vaccine in 5–11-year-old children attending the University Pediatric Hospital of Padua and Bambino-Gesù Hospital in Rome (Italy) from December-2021 to February-2023. Blood samples were collected pre-, 1-, and 6-months after vaccination. Neutralizing antibodies (NAbs) and anti-spike-receptor-binding-domain (anti-S-RBD) IgG titers were analyzed through Plaque Reduction Neutralization Test (PRNT) and chemiluminescent immune-enzymatic assay (CLIA), respectively. Immune cell phenotypes were analyzed by flow cytometry. Sixty children (26 [43 %] female, median age = 8 years [IQR = 7–10.7]) were enrolled in the study, including 46 children with a laboratory-confirmed previous COVID-19 (SARS-CoV-2-recovered) and 14 SARS-CoV-2-naïve participants defined as the absence of antigen-specific antibodies before vaccination. SARS-CoV-2-recovered participants recorded higher anti-S-RBD IgG and Wild-type and Omicron BA.2 NAbs titers than SARS-CoV-2-naïve participants at both 1- and 6-months after vaccination. Antibody titers correlated with T (Tregs) and B (Bregs) regulatory cell frequencies in SARS-CoV-2-recovered children. Both SARS-CoV-2-recovered and SARS-CoV-2-naïve participants decreased antibody titers by approximately 100 to 250 % from 1 to 6 months. While children with immunocompromising underlying conditions developed immune responses comparable to those of healthy children, solid organ transplant recipients exhibited lower levels of NAbs and anti-S-RBD IgG titers, as well as reduced frequencies of Tregs and Bregs. mRNA vaccination triggered a higher production of specific anti-SARS-CoV-2 antibodies along with increased levels of regulatory cells in children with previous SARS-CoV-2 infection up to the following 6 months. These findings provide insights into boosting pre-existing immunity.