Efforts to control the COVID-19 pandemic have expanded to the vaccination of children and adolescents. This systematic review assesses the utility of the BNT162b2 (Pfizer-BioNTech) vaccine in children and adolescents aged 5-18 years, considering its effectiveness against COVID infection, hospital and intensive care admission and duration of effectiveness after vaccination. Six databases were searched following the PRISMA guidelines. Pooled estimates and 95% confidence intervals (CIs) were calculated using meta-analysis. Fifteen studies were included in the systematic review, while 12 studies were included in the meta-analysis. Evidence suggests that the two-dose vaccination regime provided high effectiveness of 92% (95% CI, 86-96) against COVID infection. Vaccination also conferred high protection against hospitalisation (91%) and intensive care admission (85%). The vaccine was highly protective against the Delta variant of the virus, but showed a lower protection against the Omicron variant. Most adverse effects were transient and mild, commonly including pain at the injection site, fatigue and headache. Current findings are suggestive of waning immunity over time; however, further research is needed to investigate the relevance of booster doses in this age group. In summary, the Pfizer-BioNTech BNT162b2 vaccine demonstrated high levels of protection against COVID-19 infection and its complications while maintaining an adequate safety profile in children and adolescents.
Keywords: COVID-19; adolescents; children; effectiveness; vaccine.