BNT162b2 Effectiveness Against Delta and Omicron Variants of Severe Acute Respiratory Syndrome Coronavirus 2 in Adolescents Aged 12–17 Years, by Dosing Interval and Duration. (16th January 2023)

• Record Type: Journal Article
• Authors: Ionescu, Iulia G; Skowronski, Danuta M; Sauvageau, Chantal; Chuang, Erica; Ouakki, Manale; Kim, Shinhye; De Serres, Gaston
• Is Part Of: Journal of infectious diseases. Volume 227:Number 9(2023)
• Page Start: 1073
• Page End: 10783
• Publication Date: 2023-01-16
• Subjects: SARS-CoV-2 -- BNT162b2 -- COVID-19 vaccine -- adolescents -- booster dose -- test-negative design -- vaccine effectiveness -- variants of concern; Communicable diseases -- Periodicals; Diseases -- Causes and theories of causation -- Periodicals; Medicine -- Periodicals; Communicable Diseases -- Periodicals; Electronic journals; 616.9
• DOI: 10.1093/infdis/jiad006
• Languages: English
• ISSNs: 0022-1899

Abstract

Abstract: Background: Two- and 3-dose BNT162b2 vaccine effectiveness (VE) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, including Delta and Omicron variants, was assessed among adolescents in Canada, where first and second doses were spaced longer than the manufacturer-specified 3-week interval. Methods: Test-negative design estimated VE against laboratory-confirmed SARS-CoV-2 infection ≥14 days after vaccination among 12–17-year-olds in Quebec and British Columbia, Canada, between 5 September 2021 and 30 April 2022 (epidemiological weeks 36–17). VE was explored by the interval between first and second doses, time since the second dose, and with a third dose. Results: The VE against Delta was ≥90% until at least 5 months after the second dose. The VE against Omicron decreased from about 65%–75% at 2–3 weeks to ≤50% by the third month after vaccination, restored to approximately 65% by a third dose. Although confidence intervals overlapped, VE against Omicron was about 5%–7% higher (absolute) when first and second doses were spaced ≥8 versus 3–4 weeks apart. Conclusions: In adolescents, 2 BNT162b2 doses provided strong and sustained protection against Delta but reduced and rapidly waning VE against Omicron. A longer interval between first and second doses and a third dose marginally improved Omicron protection. Abstract : A test-negative-design among adolescents 12–17-years-old in Quebec and British Columbia, Canada, shows 2 BNT162b2 doses (ancestral severe acute respiratory syndrome coronavirus 2) provided strong and sustained protection against Delta but reduced and rapidly waning protection against Omicron. A longer dosing interval and a third dose marginally improved protection against Omicron.