Long-term Immune Response to SARS-CoV-2 Infection Among Children and Adults After Mild Infection.

Abstract

Importance:

Understanding the long-term immune response against SARS-CoV-2 infection in children is crucial to optimize vaccination strategies. Although it is known that SARS-CoV-2 antibodies may persist in adults 12 months after infection, data are limited in the pediatric population.

Objective:

To examine long-term anti-SARS-CoV-2 spike receptor-binding domain (S-RBD) IgG kinetics in children after SARS-CoV-2 infection.

Design, Setting, and Participants:

In this single-center, prospective cohort study, patients were enrolled consecutively from April 1, 2020, to August 31, 2021, at the COVID-19 Family Cluster Follow-up Clinic, Department of Women's and Children's Health, University Hospital of Padua. A cohort of 252 COVID-19 family clusters underwent serologic follow-up at 1 to 4, 5 to 10, and more than 10 months after infection with quantification of anti-S-RBD IgG by chemiluminescent immunoassay.

Exposures:

SARS-CoV-2 infection.

Results:

Among 902 study participants, 697 had confirmed SARS-CoV-2 infection, including 351 children or older siblings (mean [SD] age, 8.6 [5.1] years) and 346 parents (mean [SD] age, 42.5 [7.1] years). Among 697 cases, 674 (96.7%) were asymptomatic or mild. Children had significantly higher S-RBD IgG titers than older patients across all follow-up time points, with an overall median S-RBD IgG titer in patients younger than 3 years 5-fold higher than adults (304.8 [IQR, 139.0-516.6] kBAU/L vs 55.6 [24.2-136.0] kBAU/L, P < .001). Longitudinal analysis of 56 study participants sampled at least twice during follow-up demonstrated the persistence of antibodies up to 10 months from infection in all age classes, despite a progressive decline over time.

Conclusions and Relevance:

In this cohort study of Italian children and adults following SARS-CoV-2 infection different kinetics of SARS-CoV-2 antibodies were found across several age classes of individuals with asymptomatic or mild COVID-19, which could help in optimizing COVID-19 vaccination strategies and prevention policies. This work provides further evidence of sustained immune response in children up to 1 year after primary SARS-CoV-2 infection.

• Authors: Costanza Di Chiara, Anna Cantarutti, Paola Costenaro, Daniele Donà, Francesco Bonfante, Chiara Cosma, Martina Ferrarese, Sandra Cozzani, Maria Raffaella Petrara, Francesco Carmona, Cecilia Liberati, Paolo Palma, Giovanni Di Salvo, Anita De Rossi, Mario Plebani, Andrea Padoan, Carlo Giaquinto
• Journal: JAMA network open (JAMA Netw Open) Vol. 5 Issue 7 Pg. e2221616 (07 01 2022) ISSN: 2574-3805 [Electronic] United States
• PMID: 35816313 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies, Viral
• COVID-19 Vaccines
• Immunoglobulin G

Topics

• Adult
• Antibodies, Viral
• COVID-19
• COVID-19 Vaccines
• Child
• Child Health
• Cohort Studies
• Female
• Humans
• Immunity
• Immunoglobulin G
• Prospective Studies
• SARS-CoV-2
• Women's Health