tetano
Editor, Senior Moderator
Pharmacoepidemiol Drug Saf
. 2025 Nov;34(11):e70239.
doi: 10.1002/pds.70239. Impact and Effectiveness of COVID-19 mRNA Vaccination Against COVID-19 Hospitalisation in Paediatrics: A Cohort Study Using Two Linked Data Sources in Spain
Belén Castillo-Cano[SUP] 1 2 [/SUP], Fabio Riefolo[SUP] 2 3 [/SUP], Felipe Villalobos[SUP] 2 4 [/SUP], Mar Martín-Pérez[SUP] 1 2 [/SUP], Davide Messina[SUP] 5 [/SUP], Roel Elbers[SUP] 6 [/SUP], Dorieke Brink-Kwakkel[SUP] 6 [/SUP], Carlo Alberto Bissacco[SUP] 4 [/SUP], Elena Segundo[SUP] 4 [/SUP], Luis Carlos Saiz[SUP] 7 8 [/SUP], Leire Leache[SUP] 7 8 [/SUP], Elisa Barbieri[SUP] 2 9 [/SUP], Tiago Vaz[SUP] 6 [/SUP], Rosa Gini[SUP] 2 5 [/SUP], Olaf Klungel[SUP] 10 [/SUP], Elisa Martín-Merino[SUP] 1 2 [/SUP]
Affiliations
Purpose: Despite Spain's > 2 million COVID-19 paediatric cases before 2024, few required hospitalisations (8900). We aimed to estimate the effectiveness of two-dose COVID-19 vaccinations against hospitalisation 'with' and 'for' COVID-19 in paediatrics.
Methods: All individuals aged 5-14 years between January 2021 and February 2022 in two databases in Spain (SIDIAP and BIFAP) vaccinated against COVID-19 (two doses) were matched 1:1 to unvaccinated controls with the same age, sex, region and comorbidities on the dates of vaccination. Individuals with previous SARS-CoV-2 infections were excluded. COVID-19 was identified as the main reason (hospitalisation 'for' COVID-19; SIDIAP) or as one of the reasons (hospitalisation 'with' COVID-19; BIFAP) for hospitalisation with a positive SARS-CoV-2 test ±30 days. Incidence rate differences and vaccine effectiveness (VE; 95% CI; controlled by inverse probability weights) against hospitalisations 'for' and 'with' COVID-19 were calculated.
Results: The cohorts included 75 361 (SIDIAP) and 178 589 (BIFAP) pairs. Among vaccinated individuals (99.99% with mRNA vaccines) and controls, < 5 and 15 hospitalisations 'for' COVID-19 were identified (SIDIAP), whereas 21 and 32 hospitalisations 'with' COVID-19 (BIFAP), all aged 12-14 years old. Vaccination prevented 2.5 hospitalisations 'for' and 0.5 'with' COVID-19 during the Delta period, and 0.8 hospitalisations 'with' COVID-19 during Omicron predominance per 10[SUP]6[/SUP] person-days. The VE was 94% (95% CI: 52%-99%; SIDIAP) and 53% (95% CI: 18%-74%; BIFAP).
Conclusions: Given the low incidence of hospitalised COVID-19, two-dose series mRNA vaccination showed moderate-high effectiveness with few averted cases. Including hospitalisation 'with' COVID-19 underestimated the effectiveness. If paediatric severe COVID-19 remains rare, larger databases are required to understand precisely the effectiveness and impact of new vaccines.
Trial registration: EU PAS Register number: EUPAS47725.
Keywords: COVID‐19 vaccine effectiveness; children and adolescents; hospital COVID‐19 records; paediatrics; real‐word data; retrospective cohort study.
. 2025 Nov;34(11):e70239.
doi: 10.1002/pds.70239. Impact and Effectiveness of COVID-19 mRNA Vaccination Against COVID-19 Hospitalisation in Paediatrics: A Cohort Study Using Two Linked Data Sources in Spain
Belén Castillo-Cano[SUP] 1 2 [/SUP], Fabio Riefolo[SUP] 2 3 [/SUP], Felipe Villalobos[SUP] 2 4 [/SUP], Mar Martín-Pérez[SUP] 1 2 [/SUP], Davide Messina[SUP] 5 [/SUP], Roel Elbers[SUP] 6 [/SUP], Dorieke Brink-Kwakkel[SUP] 6 [/SUP], Carlo Alberto Bissacco[SUP] 4 [/SUP], Elena Segundo[SUP] 4 [/SUP], Luis Carlos Saiz[SUP] 7 8 [/SUP], Leire Leache[SUP] 7 8 [/SUP], Elisa Barbieri[SUP] 2 9 [/SUP], Tiago Vaz[SUP] 6 [/SUP], Rosa Gini[SUP] 2 5 [/SUP], Olaf Klungel[SUP] 10 [/SUP], Elisa Martín-Merino[SUP] 1 2 [/SUP]
Affiliations
- PMID: 41125425
- DOI: 10.1002/pds.70239
Purpose: Despite Spain's > 2 million COVID-19 paediatric cases before 2024, few required hospitalisations (8900). We aimed to estimate the effectiveness of two-dose COVID-19 vaccinations against hospitalisation 'with' and 'for' COVID-19 in paediatrics.
Methods: All individuals aged 5-14 years between January 2021 and February 2022 in two databases in Spain (SIDIAP and BIFAP) vaccinated against COVID-19 (two doses) were matched 1:1 to unvaccinated controls with the same age, sex, region and comorbidities on the dates of vaccination. Individuals with previous SARS-CoV-2 infections were excluded. COVID-19 was identified as the main reason (hospitalisation 'for' COVID-19; SIDIAP) or as one of the reasons (hospitalisation 'with' COVID-19; BIFAP) for hospitalisation with a positive SARS-CoV-2 test ±30 days. Incidence rate differences and vaccine effectiveness (VE; 95% CI; controlled by inverse probability weights) against hospitalisations 'for' and 'with' COVID-19 were calculated.
Results: The cohorts included 75 361 (SIDIAP) and 178 589 (BIFAP) pairs. Among vaccinated individuals (99.99% with mRNA vaccines) and controls, < 5 and 15 hospitalisations 'for' COVID-19 were identified (SIDIAP), whereas 21 and 32 hospitalisations 'with' COVID-19 (BIFAP), all aged 12-14 years old. Vaccination prevented 2.5 hospitalisations 'for' and 0.5 'with' COVID-19 during the Delta period, and 0.8 hospitalisations 'with' COVID-19 during Omicron predominance per 10[SUP]6[/SUP] person-days. The VE was 94% (95% CI: 52%-99%; SIDIAP) and 53% (95% CI: 18%-74%; BIFAP).
Conclusions: Given the low incidence of hospitalised COVID-19, two-dose series mRNA vaccination showed moderate-high effectiveness with few averted cases. Including hospitalisation 'with' COVID-19 underestimated the effectiveness. If paediatric severe COVID-19 remains rare, larger databases are required to understand precisely the effectiveness and impact of new vaccines.
Trial registration: EU PAS Register number: EUPAS47725.
Keywords: COVID‐19 vaccine effectiveness; children and adolescents; hospital COVID‐19 records; paediatrics; real‐word data; retrospective cohort study.