García-García E, Calle-Miguel L, Pérez-Solís D, Urueña IC, Merino ÁG, Gómez HH, Poladura MM, Rodríguez-Pérez M. Household Transmission of SARS-CoV-2 and Long-term Immunity in Children: A Prospective Study in Northern Spain.
Pediatr Infect Dis J 2023;
42:226-231. [PMID:
36730092 PMCID:
PMC9935233 DOI:
10.1097/inf.0000000000003790]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/01/2022] [Indexed: 02/03/2023]
Abstract
BACKGROUND
The role of children in SARS-CoV-2 transmission and their immune response after infection have been profoundly discussed. Hereby, we analyze both aspects in a Spanish pediatric population.
METHODS
Prospective, multicentre, longitudinal study performed from July 2020 to September 2021 in children up to 14 years old. Venous blood samples were collected every 6 months and serum was analyzed for antibodies against SARS-CoV-2 using a spike (S) and a nucleocapsid (N) protein assays. Household contacts of seropositive children were tested. Household transmission, antibody dynamics, and durability were analyzed.
RESULTS
Two hundred children were recruited and 28 had SARS-CoV-2 antibodies at the end of the study, resulting in an overall seroprevalence of 16.6% (95% CI: 9.5%-19.6%). Most of children (18/28) were secondary cases. The secondary attack rate (SAR) was lower in households with pediatric index cases than in those with adult index cases ( P = 0.023). The median antibody titers in the first positive serology, for the seropositive patients, were 137 BAU/mL (IQR 83.3-427.4) for the S-assay and 132.5 COI (IQR 14.5-170.5) for the N-assay without significant differences between symptomatic and asymptomatic children. The median time between the RT-PCR and the last serology was 7.5 months (IQR 5.2-8.8), and the duration of SARS-CoV-2 antibodies after infection was proven to be at least 18 months. There were no cases of seroreversion.
CONCLUSIONS
(1) Children are not the main drivers of SARS-CoV-2 household transmission. (2) They maintain SARS-CoV-2 antibodies for up to 18 months after infection and the titers are similar between symptomatic and asymptomatic children.
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