Interim Estimates of COVID-19 Vaccine Effectiveness Against COVID-19-Associated Emergency Department or Urgent Care Clinic Encounters and Hospitalizations Among Adults During SARS-CoV-2 B.1.617.2 (Delta) Variant Predominance - Nine States, June-August 2021

• Published in: MMWR. Morbidity and mortality weekly report Vol. 70; no. 37; pp. 1291 - 1293
• Main Authors: Grannis, Shaun J, Rowley, Elizabeth A, Ong, Toan C, Stenehjem, Edward, Klein, Nicola P, DeSilva, Malini B, Naleway, Allison L, Natarajan, Karthik, Thompson, Mark G
• Format: Journal Article Newsletter
• Language: English
• Published: United States U.S. Government Printing Office 17.09.2021; U.S. Center for Disease Control; Centers for Disease Control and Prevention
• Subjects: Abbreviations; Adolescent; Adult; Adults; Age; Age groups; Aged; Ambulatory Care Facilities - statistics & numerical data; Confidence intervals; Coronaviruses; Cough; COVID-19; COVID-19 - epidemiology; COVID-19 - prevention & control; COVID-19 - therapy; COVID-19 - virology; COVID-19 vaccines; COVID-19 Vaccines - administration & dosage; COVID-19 Vaccines - immunology; Diarrhea; Drug dosages; Dyspnea; Effectiveness; Emergency medical care; Emergency medical services; Emergency medicine; Emergency service; Emergency Service, Hospital - statistics & numerical data; Federal agencies; Full Report; Hospitalization; Hospitalization - statistics & numerical data; Hospitals; Humans; Illnesses; Informatics; Medical laboratories; Medical research; Medicine, Experimental; Middle Aged; mRNA vaccines; Patients; Polymerase chain reaction; Population studies; Respiration; Reverse transcription; SARS-CoV-2; Severe acute respiratory syndrome coronavirus 2; Signs and symptoms; United States - epidemiology; Vaccination; Vaccine efficacy; Vaccines; Viral diseases; Viruses; Vomiting; Young Adult; United States; California; United States > US; Minnesota
• ISSN: 0149-2195; 1545-861X
• DOI: 10.15585/MMWR.MM7037E2

Data on COVID-19 vaccine effectiveness (VE) since the B.1.617.2 (Delta) variant of SARS-CoV-2, the virus that causes COVID-19, became the predominant circulating strain in the United States are limited (1-3). CDC used the VISION Network* to examine medical encounters (32,867) from 187 hospitals and 221 emergency departments (EDs) and urgent care (UC) clinics across nine states during June-August 2021, beginning on the date the Delta variant accounted for >50% of sequenced isolates in each medical facility's state. VISION Network methods have been published (4).