In a recent study, two doses of the BNT162b2 vaccine offered substantial protection in adolescents against Omicron infection in the first 3 months following their second dose. Malcolm Risk et al. aimed to estimate booster dose effectiveness and BNT162b2 vaccine effectiveness (VE) in adolescents (12 to 17 years of age) and the effect of the Omicron variant and opening schools on COVID-19 infection risk in adolescents.

In order to calculate BNT162b2 VE and the efficacy of a booster dosage in adolescents, a test-negative design with logistic regression was utilized. To determine if the risk for adolescents elevated in comparison to the reference group once school started, Cox proportional hazards regression was utilized to compare adolescents to adults aged 22–33 or 65+ years (reference group).

Adolescents who got 2 dosages of BNT162b2 experienced considerable protection from Omicron infection in the first 3 months after their second dosage (VE = 54.5%). But, no further protection was noted. A booster dosage restored effectiveness to a comparable level (VE = 56.3%) and reduced infection risk (odds ratio = 0.48). Compared to adults, there was a clinically meaningful rise in adolescent infection risk during the Omicron predominance.

The BNT162b2 vaccination proved effective in protecting adolescents against SARS-CoV-2 infection, but protection against Omicron quickly wears off and requires booster shots to maintain. The effect of reopening schools on COVID-19 infection risk during the Omicron-dominant phase requires further investigation.