Vaccine Effectiveness Against COVID-19 Infection Among 12 to 18 year olds in Singapore

Abstract

We studied the incidence of confirmed COVID-19 infection and symptomatic infection among adolescents aged 12 to 18 years old vaccinated with Pfizer-BioNTech/Comirnaty in Singapore. Full vaccination with 2 doses achieved vaccine effectiveness of 59% (95% CI 55% – 63%) against confirmed infection and 62% (95% CI 57% – 66%) against symptomatic infection, compared with unvaccinated adolescents. Among those fully vaccinated, gradual waning of immunity was observed over 4 months from completion of the second dose.

Note:
Funding: Funding: This study was not funded.

Declaration of Interests: The authors declare that they have no conflict of interest.

Ethics Approval Statement: This study was conducted as part of national COVID-19 public health response under the Infectious Disease Act, Ministry of Health, Singapore, with exemption from ethics review, as provided for under the Human Biomedical Research Act 2015, Singapore.

Keywords: COVID-19, SARS-CoV-2, vaccines, mRNA vaccine, adolescent