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. 2025 May 23;44(9):e319-e321.
doi: 10.1097/INF.0000000000004869.

Childhood Humoral Immunity During and After COVID-19 Lockdowns

Coralie Mallebranche  1 , Emeline Vinatier  2 , Julien Lejeune  3 , Tiffanie Bousser  4 , Marie-Alexandra Alyanakian  5 , Céline Beauvillain  6 , Vannina Giacobbi  7 , Isabelle Pellier  1 , Charline Miot  6
Affiliations

Childhood Humoral Immunity During and After COVID-19 Lockdowns

Coralie Mallebranche et al. Pediatr Infect Dis J. .

Abstract

Our study, including serum from 3678 hospital inpatients and outpatients sampled before, during and after the COVID-19 lockdown periods, showed a significant decrease in overall IgG levels during the periods of sanitary restriction, particularly in children 3-10 years of age. Few months after the lifting of COVID-19 restrictions, immunoglobulin levels normalized. COVID-19 lockdowns may have induced a transient humoral immune gap.

Keywords: Immunoglobulin G; Immunologic Memory; SARS-CoV-2; non-pharmaceutical interventions.

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Conflict of interest statement

The authors have no funding or conflicts of interest to disclose.

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