Eurosurv. COVID-19 vaccine effectiveness in the paediatric population aged 5–17 years: a multicentre cohort study using electronic health registries i

[tetano]

• Patrícia Soares[SUP]1,*[/SUP] , Ausenda Machado[SUP]1,*[/SUP] , Nathalie Nicolay[SUP]2[/SUP] , Susana Monge[SUP]3,4[/SUP] , Chiara Sacco[SUP]5[/SUP] , Christian Holm Hansen[SUP]6[/SUP] , Hinta Meijerink[SUP]7[/SUP] , Iván Martínez-Baz[SUP]4,8[/SUP] , Susanne Schmitz[SUP]9[/SUP] , James Humphreys[SUP]10[/SUP] , Massimo Fabiani[SUP]5[/SUP] , Aitziber Echeverria[SUP]8[/SUP] , Ala’a AlKerwi[SUP]9[/SUP] , Anthony Nardone[SUP]10[/SUP] , Alberto Mateo-Urdiales[SUP]5[/SUP] , Jesús Castilla[SUP]4,8[/SUP] , Esther Kissling[SUP]10[/SUP] , Baltazar Nunes[SUP]1,10[/SUP] , VEBIS-Lot 4 working group[SUP]11[/SUP]

Background

During the first year of the COVID-19 pandemic, vaccination programmes targeted children and adolescents to prevent severe outcomes of SARS-CoV-2 infection.


Aim

To estimate COVID-19 vaccine effectiveness (VE) against hospitalisation due to COVID-19 in the paediatric population, among those with and without previously documented SARS-CoV-2 infection.


Methods

We established a fixed cohort followed for 12 months in Denmark, Norway, Italy, Luxembourg, Navarre (Spain) and Portugal using routine electronic health registries. The study commenced with paediatric COVID-19 vaccination campaign at each site between June 2021 and January 2022. The outcome was hospitalisation with a laboratory-confirmed SARS-CoV-2 infection or COVID-19 as the main diagnosis. Using Cox proportional hazard models, VE was estimated as 1 minus the confounder-adjusted hazard ratio of COVID-19 hospitalisation between vaccinated and unvaccinated. A random-effects meta-analysis was used to pool VE estimates.


Results

We included 4,144,667 5–11-year-olds and 3,861,841 12–17-year-olds. In 12–17-year-olds without previous infection, overall VE was 69% (95% CI: 40 to 84). VE declined with time since vaccination from 77% ≤ 3 months to 48% 180–365 days after immunisation. VE was 94% (95% CI: 90 to 96), 56% (95% CI: 3 to 80) and 41% (95% CI: −14 to 69) in the Delta, Omicron BA.1/BA.2 and BA.4/BA.5 periods, respectively. In 12–17-year-olds with previous infection, one dose VE was 80% (95% CI: 18 to 95). VE estimates were similar for 5–11-year-olds but with lower precision.


Conclusion

Vaccines recommended for 5–17-year-olds provided protection against COVID-19 hospitalisation, regardless of a previously documented infection of SARS-CoV-2, with high levels of protection in the first 3 months of the vaccination

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https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2025.30.8.2400450

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