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Course: Effectiveness Associated With BNT162b2 Vaccine Against Emergency Department and Urgent Care Encounters for Delta and Omicron SARS-CoV-2 Infection Among Adolescents Aged 12 to 17 Years

CME Credits: 1.00

Released: 2022-08-03

Key Points

Question What is the durability associated with 2 doses of the BNT162b2 COVID-19 vaccine against Delta- and Omicron-related emergency department and urgent care encounters among adolescents aged 12 to 17 years, and is a third dose associated with improved protection?
Findings In this case-control study including 3168 adolescents, estimated effectiveness of 2 doses of BNT162b2 was highest against both Delta (89%) and Omicron (73%) less than 2 months after vaccination but waned to 49% against Delta and 16% against Omicron at 6 months and beyond. Estimated effectiveness of 3 doses of BNT162b2 against Omicron was 87%.
Meaning These findings suggest that third doses are needed to achieve peak protection for adolescents and may help mitigate against a future surge in cases.

Abstract

Importance Data about the duration of protection of 2 and 3 doses of BNT162b2 in children and adolescents are needed to help inform recommendations for boosters in this age group.
Objective To evaluate vaccine effectiveness (VE) and durability associated with 2 doses of BNT162b2 against Delta- and Omicron-related emergency department (ED) and urgent care (UC) encounters among adolescents aged 12 to 17 years and to estimate VE associated with 3 doses against these same outcomes.
Design, Setting, and Participants This test-negative case-control study was conducted at Kaiser Permanente Southern California, an integrated health care system using electronic health records in the US. Participants included Kaiser Permanente Southern California members ages 12 to 17 years with an ED or UC encounter from November 1, 2021, through March 18, 2022, for acute respiratory infection who were tested for SARS-CoV-2 via a reverse transction–polymerase chain reaction test. Analyses were conducted from March 21 to June 22, 2022.
Exposures BNT162b2 vaccination status ascertained from electronic health records and state registry data.
Main Outcomes and Measures The main outcome was VE associated with BNT162b2 against ED and UC encounters related to Delta or Omicron variant SARS-CoV-2 infection.
Results Analyses were conducted among 3168 adolescents, including 1004 with ED visits and 2164 with UC visits. Median (IQR) age was 15 (13-16) years, and 1461 (46.1%) were boys. In adjusted analyses, VE associated with 2 doses of BNT162b2 against ED or UC encounters was highest within the first 2 months for both Delta (89% [95% CI, 69% to 96%]) and Omicron (73% [95% CI, 54% to 84%]) variants but waned to 49% (95% CI, 27% to 65%) for the Delta variant and 16% (95% CI, -7% to 34%) for the Omicron variant at 6 months and beyond. A third dose of BNT162b2 was associated with improved protection against the Omicron variant (87% [95% CI, 72% to 94%]) after a median (IQR) of 19 (9-32) days after dose 3.
Conclusions and Relevance These findings suggest that 2 doses of the BNT162b2 COVID-19 vaccine were associated with high levels of protection against ED and UC encounters related to the Delta and Omicron variants of SARS-CoV-2 in the first few months after vaccination. However, effectiveness waned over time, especially against Omicron. A third dose of BNT162b2 was associated with improved protection against Omicron beyond that seen initially after 2 doses, underscoring the importance of boosters for adolescents aged 12 to 17 years.


Educational Objective
To identify the key insights or developments described in this article


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