Variation in the time to complete the primary COVID-19 vaccine series by race, ethnicity, and geography among older US adults

Vaccine. 2025 Jan 1;43(Pt 2):126501. doi: 10.1016/j.vaccine.2024.126501. Epub 2024 Nov 7.

Abstract

Introduction: Racial and ethnic disparities in COVID-19 vaccine access are well-documented; however, few studies have examined whether racial disparities are modified by other factors, including geographic location and area-level deprivation.

Methods: We conducted an observational study using the COVVAXAGE database. Medicare beneficiaries who received the COVID-19 vaccine primary series (two doses) between 01/01/2021 and 12/31/2021 were included. Racial differences in the time between doses was assessed by urbanicity using g-formula methods.

Results: We identified 11,924,990 beneficiaries (mean age = 75.4; 60 % female; 80 % White). Most beneficiaries (97.1 %) received their second vaccine on time. Delayed second doses were more common among beneficiaries who were Black (RRdelayed = 1.30, 95 %CI = 1.28-1.31) and rural (RRdelayed = 1.27, 95 %CI = 1.25-1.29) relative to White and urban beneficiaries. Racial disparities in delayed vaccinations varied in magnitude by degree of urbanicity.

Conclusions: Most beneficiaries received their second COVID-19 vaccine on time. Racial disparities were observed and shown to vary by geographic area.

Keywords: COVID-19; Health disparities; Vaccination schedule; mRNA vaccines.

Publication types

  • Observational Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • COVID-19 Vaccines* / administration & dosage
  • COVID-19* / epidemiology
  • COVID-19* / prevention & control
  • Ethnicity* / statistics & numerical data
  • Female
  • Geography
  • Healthcare Disparities / statistics & numerical data
  • Humans
  • Male
  • Medicare / statistics & numerical data
  • Racial Groups / statistics & numerical data
  • Time Factors
  • United States
  • Vaccination / statistics & numerical data

Substances

  • COVID-19 Vaccines