background and objectives: 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. Methods: 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. results: 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. conclusions: 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.

Di Chiara, C., Cantarutti, A., Raffaella Petrara, M., Bonfante, F., Benetti, E., Boracchini, R., et al. (2023). Stronger and durable SARS-CoV-2 immune response to mRNA vaccines in 5–11 years old children with prior COVID-19. VACCINE [10.1016/j.vaccine.2023.12.006].

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

Nicola Cotugno;
2023-12-08

Abstract

background and objectives: 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. Methods: 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. results: 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. conclusions: 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.
8-dic-2023
Online ahead of print
Rilevanza internazionale
Articolo
Esperti anonimi
Settore MED/38
English
5–11-year-old children
BNT162b2 mRNA COVID-19 vaccine
Comirnaty
SARS-CoV-2 anti-S-RBD antibody
SARS-CoV-2 neutralizing antibodies
T and B regulatory cells
inglese
Di Chiara, C., Cantarutti, A., Raffaella Petrara, M., Bonfante, F., Benetti, E., Boracchini, R., et al. (2023). Stronger and durable SARS-CoV-2 immune response to mRNA vaccines in 5–11 years old children with prior COVID-19. VACCINE [10.1016/j.vaccine.2023.12.006].
Di Chiara, C; Cantarutti, A; Raffaella Petrara, M; Bonfante, F; Benetti, E; Boracchini, R; Bosa, L; Carmona, F; Cosma, C; Cotugno, N; Le Prevost, M; Martini, G; Meneghel, A; Pagliari, M; Palma, P; Ruffoni, E; Zin, A; De Rossi, A; Giaquinto, C; Donà, D; Padoan, A
Articolo su rivista
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/345704
Citazioni
  • ???jsp.display-item.citation.pmc??? 0
  • Scopus 2
  • ???jsp.display-item.citation.isi??? 0
social impact