Averaged weekly, age-standardized rates (events per 100,000 persons) were higher among persons not fully vaccinated than among fully vaccinated persons for reported cases (112.3 versus 10.1), hospitalizations (9.1 versus 0.7), and deaths (1.6 versus 0.1) during April 4–June 19, as well as during June 20–July 17 (89.1 versus 19.4; 7.0 versus 0.7; 1.1 versus 0.1, respectively). Higher hospitalization and death rates were observed in older age groups, regardless of vaccination status, resulting in a larger impact of age-standardization on overall incidence for these outcomes.
Within each age group, the percentage of vaccinated persons among cases, hospitalizations, and deaths increased with increasing vaccination coverage (Figure 1). As the prevalence of SARS-CoV-2 Delta variant surpassed 50%, the percentage of vaccinated persons among cases in each age group increased at rates corresponding to benchmarks for lower VE (i.e., from approximately 90% to <80%). Increases in the percentages of vaccinated persons aged ≥65 years among COVID-19–associated hospitalizations and deaths also appeared higher than expected. During June 20–July 17, age-standardized rates of cases, hospitalizations, and deaths among persons not fully vaccinated increased weekly; among fully vaccinated persons, case rates increased, but rates of hospitalizations and deaths remained largely unchanged (Figure 2).
Author(s): Heather M. Scobie, PhD1; Amelia G. Johnson, DrPH1; Amitabh B. Suthar, PharmD2; Rachel Severson, MS3; Nisha B. Alden, MPH3; Sharon Balter, MD4; Daniel Bertolino, MPH5; David Blythe, MD6; Shane Brady, MPH7; Betsy Cadwell, MSPH1; Iris Cheng, MS5; Sherri Davidson, PhD8; Janelle Delgadillo9; Katelynn Devinney, MPH5; Jeff Duchin, MD10; Monique Duwell, MD6; Rebecca Fisher, MPH4; Aaron Fleischauer, PhD11; Ashley Grant, MPH12; Jennifer Griffin, PhD4; Meredith Haddix, MPH4; Julie Hand, MSPH12; Matt Hanson, MD10; Eric Hawkins, MS13; Rachel K. Herlihy, MD3; Liam Hicks, MPH7; Corinne Holtzman, MPH14; Mikhail Hoskins, MPH11; Judie Hyun, MHS6; Ramandeep Kaur, PhD8; Meagan Kay, DVM10; Holly Kidrowski, MPH14; Curi Kim, MSPH6; Kenneth Komatsu, MPH7; Kiersten Kugeler, PhD1; Melissa Lewis, MPH1; B. Casey Lyons, MPH2; Shelby Lyons, MPH12; Ruth Lynfield, MD14; Keegan McCaffrey7; Chelsea McMullen, MS15; Lauren Milroy, MPH13; Stephanie Meyer, MPH14; Leisha Nolen, MD9; Monita R. Patel, PhD1; Sargis Pogosjans, MPH10; Heather E. Reese, PhD1; Amy Saupe, MPH14; Jessica Sell, MPH5; Theresa Sokol, MPH12; Daniel Sosin, MD15; Emma Stanislawski, MPH15; Kelly Stevens, MS8; Hailey Vest, MPH13; Kelly White, MPH13; Erica Wilson, MD11; Adam MacNeil, PhD1; Matthew D. Ritchey2; Benjamin J. Silk, PhD1
Publication Date: 10 Sept 2021
Publication Site: CDC, Morbidity and Mortality Weekly Report