RELATIVE VACCINE EFFECTIVENESS OF THE CO-ADMINISTRATION OF INFLUENZA AND COVID-19 VACCINES COMPARED TO INFLUENZA ALONE, AMONG CHILDREN IN THE US IN FALL 2023-2024
Author(s)
Isabelle Winer, MPH, Ni Zeng, PhD, Taylor Ryan, MHI, Maria Weck, MPH, Jessamine Winer-Jones, PhD, Janna Manjelievskaia, MPH, PhD, Alina Bogdanov, MA.
Veradigm, Raleigh, NC, USA.
Veradigm, Raleigh, NC, USA.
OBJECTIVES: This study examined the relative vaccine effectiveness (rVE) of the co-administration of influenza and COVID-19 vaccines compared to influenza-vaccinated alone among US children during the fall 2023-2024 season.
METHODS: This retrospective analysis identified children (<18) in the Veradigm Network EHR linked to Komodo claims who received a COVID-19 or influenza vaccine between 09/12/2023 and 01/30/2024 (earliest event = index date), with follow-up ending 04/30/2024. Patients with missing age or sex, evidence of prior influenza vaccination during the same season, or evidence of COVID-19 or influenza diagnosis in the 90 days prior through 14 days after index were excluded. Patients were required to have ≥12 months of claims enrollment before and ≥15 days after the index date. Adjusted rVE against COVID-19- and influenza-related visits and hospitalizations were estimated using Cox regression; rVE = 100 x (1 - hazard ratio [HR]). Model covariates included age, sex, race, region, week of index, and high-risk status. Patients were stratified by index vaccine: co-vaccinated (second vaccination within 14 days of the first), influenza-only.
RESULTS: 62,244 co-vaccinated children and 405,028 influenza-vaccinated children were eligible for study. Mean (SD) age was 11.7 (4.2) years for co-vaccinated and 9.8 (4.6) years for influenza-only; 6.5% of co-vaccinated children and 15.9% of influenza-vaccinated children were ages 0-4. October was the most common month of index for both cohorts, but co-vaccinated children typically indexed later in the season than influenza-vaccinated only. The adjusted rVE (95% CI) for co-vaccination versus influenza-only was 51.3% (45.9%-56.1%) against COVID-19-related visits and 41.9% (-35.5%-75.1%) against COVID-19-related hospitalizations. The rVE was 12.9% (8.4%-17.1%) for influenza-related visits and 10.3% (-74.8%-54.0%) for influenza-related hospitalizations.
CONCLUSIONS: Compared to influenza vaccination alone, co-administration of the COVID vaccine was associated with significant effectiveness in preventing not only COVID-19-related visits, but also influenza-related visits among children in the US during the 2023-2024 season.
METHODS: This retrospective analysis identified children (<18) in the Veradigm Network EHR linked to Komodo claims who received a COVID-19 or influenza vaccine between 09/12/2023 and 01/30/2024 (earliest event = index date), with follow-up ending 04/30/2024. Patients with missing age or sex, evidence of prior influenza vaccination during the same season, or evidence of COVID-19 or influenza diagnosis in the 90 days prior through 14 days after index were excluded. Patients were required to have ≥12 months of claims enrollment before and ≥15 days after the index date. Adjusted rVE against COVID-19- and influenza-related visits and hospitalizations were estimated using Cox regression; rVE = 100 x (1 - hazard ratio [HR]). Model covariates included age, sex, race, region, week of index, and high-risk status. Patients were stratified by index vaccine: co-vaccinated (second vaccination within 14 days of the first), influenza-only.
RESULTS: 62,244 co-vaccinated children and 405,028 influenza-vaccinated children were eligible for study. Mean (SD) age was 11.7 (4.2) years for co-vaccinated and 9.8 (4.6) years for influenza-only; 6.5% of co-vaccinated children and 15.9% of influenza-vaccinated children were ages 0-4. October was the most common month of index for both cohorts, but co-vaccinated children typically indexed later in the season than influenza-vaccinated only. The adjusted rVE (95% CI) for co-vaccination versus influenza-only was 51.3% (45.9%-56.1%) against COVID-19-related visits and 41.9% (-35.5%-75.1%) against COVID-19-related hospitalizations. The rVE was 12.9% (8.4%-17.1%) for influenza-related visits and 10.3% (-74.8%-54.0%) for influenza-related hospitalizations.
CONCLUSIONS: Compared to influenza vaccination alone, co-administration of the COVID vaccine was associated with significant effectiveness in preventing not only COVID-19-related visits, but also influenza-related visits among children in the US during the 2023-2024 season.
Conference/Value in Health Info
2026-11, ISPOR Europe 2026, Vienna, Austria
Value in Health, Volume 29, Issue 12S
Code
CO93
Topic
Clinical Outcomes, Epidemiology & Public Health
Topic Subcategory
Comparative Effectiveness or Efficacy
Disease
Pediatrics, Vaccines