Adolescent vaccination with BNT162b2 (Comirnaty, Pfizer-BioNTech) vaccine and effectiveness against COVID-19: national test-negative case-control study, England

Abstract

Adolescents in the UK were recommended to have their first dose of mRNA vaccine during a period of high community transmission due to the highly transmissible Delta variant, followed by a second dose at an extended interval of 8-12 weeks. We used national SARS-CoV-2 testing, vaccination and hospitalisation data to estimate vaccine effectiveness (VE) using a test-negative case-control design, against PCR-confirmed symptomatic COVID-19 in England. VE against symptomatic disease increased to 80% within two weeks of the first dose of BNT162b2 vaccine (higher than in adults aged 18-64 years) and then declines rapidly to 40% within 8 weeks (similar to adults). Early data in 16-17-year-olds also indicate high protection against hospitalisation and a rapid increase in VE against symptomatic COVID-19 after the second dose. Our data highlight the importance of the second vaccine dose for protection against symptomatic COVID-19 and raise important questions about the objectives of an adolescent immunisation programme. If prevention of infection is the primary aim, then regular COVID-19 vaccine boosters will be required.

Vaccine effectiveness with BNT162b2 (Comirnaty, Pfizer-BioNTech) vaccine against reported SARS-CoV-2 Delta and Omicron infection among adolescents, Norway, August 2021 to January 2022

“…Vaccine effectiveness above 90% against the Delta variant 7-62 days after the second dose is in line with results from other studies among adolescents in England, Israel, and USA even though different study designs were used (6,9,10). A reduced effectiveness of the mRNA vaccines against infection with the Omicron variant compared to the Delta variant has been documented in several preprint studies, primarily in adults (14-16), but also in one preprint study in adolescents in England (9).…”

“…Vaccine effectiveness above 90% against the Delta variant 7-62 days after the second dose is in line with results from other studies among adolescents in England, Israel, and USA even though different study designs were used (6,9,10). A reduced effectiveness of the mRNA vaccines against infection with the Omicron variant compared to the Delta variant has been documented in several preprint studies, primarily in adults (14-16), but also in one preprint study in adolescents in England (9). In our study we found no protective effect after one dose, but the study from England among adolescents estimated that vaccine effectiveness against symptomatic Omicron infection after one dose peaked at 50% in days 14-20 after vaccination among 12-15-year-olds and at 53% in days 21-27 after vaccination among 16-17-year-olds.…”

“…The effectiveness of BNT162b2 in adolescents has also been demonstrated in observational studies from Israel, the USA, and England, showing very good protection against infection with the Delta variant after the second dose (6-9). The effectiveness of one dose and of the second dose among adolescents against symptomatic Omicron infection has been explored in a study from England published as a preprint, but the evidence is still limited (9).…”

“…In addition, BNT162b2 (Comirnaty, Pfizer-BioNTech) and mRNA-1273 (Spikevax, Moderna) vaccines have been approved for use in adolescents, based on results from randomized placebo-controlled trials demonstrating comparable immunogenicity and safety profile as in young adults (4,5). The effectiveness of BNT162b2 in adolescents has also been demonstrated in observational studies from Israel, the USA, and England, showing very good protection against infection with the Delta variant after the second dose (6)(7)(8)(9). The effectiveness of one dose and of the second dose among adolescents against symptomatic Omicron infection has been explored in a study from England published as a preprint, but the evidence is still limited (9).…”

Effectiveness of the BNT162b2 vaccine among children 5-11 and 12-17 years in New York after the Emergence of the Omicron Variant

“…[1][2][3][4][5][6][7][8][9][10] Compared to children 12-17 years, who receive two 30g doses, less is known known about real-world vaccine effectiveness against infection and hospitalization effectiveness for children 5-11 years, who receive two 10g doses, particularly after the Omicron variant's emergence. 11,12 We examined the effectiveness of vaccination during the Omicron variant surge that began in early December 2021 on infection and hospitalization among children 5-11 years compared to 12-17 years using NYS statewide surveillance systems.…”