BNT162b2 COVID-19 vaccination uptake, safety, effectiveness, and waning in children and young people aged 5-11 years in Scotland.

Abstract

Background: Few large-scale population studies have examined both safety and vaccine effectiveness (VE) specifically for 5-11-year-olds during the Omicron-dominant period in a setting with low vaccine uptake. The BNT162b2 (Pfizer-BioNTech) vaccine, administered in two doses, has shown strong efficacy against symptomatic and severe COVID-19 in clinical trials involving children and young people (CYP). Accordingly, we examined the uptake, real-world safety, VE, and waning of BNT162b2 VE against symptomatic COVID-19 among children aged 5-11 years in Scotland.

Methods: This national prospective cohort study used the Scotland-wide Early Pandemic Evaluation and Enhanced Surveillance of COVID-19 (EAVE II) platform. We evaluated vaccine uptake using national data from the Turas Vaccination Management Tool, up to 16 April 2024. We assessed vaccine safety through national records on hospital admissions, employing a self-controlled case series design to examine 17 predefined health outcomes. We estimated VE against symptomatic, COVID-19 infection confirmed by reverse transcription-polymerase chain reaction and caused by the Omicron variant using a test-negative design.

Results: From 19 March 2022 to 1 January 2023, 25.3% of the 392 658 children aged 5-11 years received their first COVID-19 vaccine dose and 16.2% completed the second dose. We found no increased risk of safety related hospital admission for 17 health outcomes in the post-vaccination period. During the Omicron period, VE against symptomatic COVID-19 was 60.8% (95% confidence interval (CI) = 0.3-84.5%) at 2-26 weeks post-first dose and 41.6% (95% CI = -89.6, 82.0) at 2-26 weeks post-second dose. The protective effect against symptomatic disease was no longer detectable in the period ≥27 weeks following both the first and second doses.

Conclusions: The BNT162b2 vaccine demonstrated a strong safety profile in this age group. Receiving both doses was linked to a reduction in the risk of symptomatic COVID-19 during the Omicron variant period, but this protection waned over the following six months.