COVID-19 vaccine effectiveness in children by age groups. A population-based study in Galicia, Spain

Background: Studies on vaccine effectiveness (VE) against COVID-19 in the pediatric population are outgoing. We aimed to quantify VE against SARS-CoV-2 in two pediatric age groups, 5-11 and 12-17-year-old, while considering vaccine type, SARS-CoV-2 variant, and duration of protection. Methods: A pop...

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Bibliographic Details
Authors: Mallah ., Narmeen, Pardo Seco, Jacobo José, Ares Gómez, María Sonia, López Pérez, Luis Ricardo, González Pérez, Juan Manuel, Rosón Calvo, Benigno, Otero Barrós, María Teresa, Durán Parrondo, Carmen, Nartallo Penas, Victoria, Mirás Carballal, Susana, Rodríguez-Tenreiro Sánchez, Carmen, Rivero Calle, Irene, Gómez Carballa, Alberto, Salas Ellacuriaga, Antonio, Martinón Torres, Federico
Format: article
Publication Date:2023
Country:España
Institution:Servizo Galego de Saúde (SERGAS)
Repository:RUNA. Repositorio da Consellería de Sanidade e Sergas
OAI Identifier:oai:runa.sergas.gal:20.500.11940/21286
Online Access:https://portalcientifico.sergas.gal//documentos/6546ece532348009d228e7a3
http://hdl.handle.net/20.500.11940/21286
Access Level:Open access
Keyword:Child
Humans
Child, Preschool
Adolescent
COVID-19 Vaccines
SARS-CoV-2
COVID-19
Spain
2019-nCoV Vaccine mRNA-1273
BNT162 Vaccine
Vaccine Efficacy
AS Santiago
IDIS
DXSP
CHUS
Description
Summary:Background: Studies on vaccine effectiveness (VE) against COVID-19 in the pediatric population are outgoing. We aimed to quantify VE against SARS-CoV-2 in two pediatric age groups, 5-11 and 12-17-year-old, while considering vaccine type, SARS-CoV-2 variant, and duration of protection. Methods: A population-based test-negative control study was undertaken in Galicia, Spain. Children 5-11-year-old received the Comirnaty® (Pfizer, US) vaccine, while those aged 12-17-year-old received the Comirnaty® (Pfizer, US) or SpikeVax® (ModernaTX, Inc) vaccine. Participants were categorized into unvaccinated (0 doses or one dose with <14 days since vaccination), partially vaccinated (only one dose with ?14 days, or two doses with <14 days after the second dose administration), and fully vaccinated (two doses with ?14 days after the second injection). Adjusted odds ratios (OR) and their 95% confidence intervals (CI) were estimated using multiple logistic regression models. VE was calculated as (1-OR) * 100. Stratified and sensitivity analyses were performed. Results: In the fully vaccinated 5-11-year-old children, VE against the Omicron variant was 44.1% (95% CI: 38.2%-49.4%). In the fully vaccinated 12-17-year-old individuals, VE was 83.4% (95% CI: 81.2%-85.3%) against Delta and 74.8% (95% CI: 58.5%-84.9%) against Omicron. Comirnaty® and SpikeVax® vaccines showed a similar magnitude of VE against Delta [Comirnaty® VE: 81.9% (95% CI: 79.3%-84.1%) and SpikeVax® VE: 85.3% (95% CI: 81.9%-88.1%)]. Comirnaty® (Pfizer, US; VE: 79.7%; 95% CI: 50.7%-92.4%) showed a slightly higher magnitude of protection against Omicron than SpikeVax® (ModernaTX, Inc), yet with an overlapping CI (VE: 74.3%; 95% CI: 56.6%-84.9%). VE was maintained in all age subgroups in both pediatric populations, but it declined over time. Conclusions: In Galicia, mRNA VE was moderate against SARS-CoV-2 infections in the 5-11-year-old populations, but high in older children. VE declined over time, suggesting a potential need for booster dose schedules.