U.S. Department of Health & Human Services
09/17/2021 | Press release | Distributed by Public on 09/17/2021 04:20
COVID Data Tracker Recent Updates - 2021-09-16 - Crosslinks to CDC Vaccination Effectiveness Research webpage have been added to multiple tabs across the site
Before the U.S. Food and Drug Administration (FDA) determines whether to approve a vaccine or authorize a vaccine for emergency use, clinical trials are conducted to determine vaccine efficacy.
After FDA approves a vaccine or authorizes a vaccine for emergency use, it continues to be studied to determine how well it works under real-world conditions. CDC and other federal partners will be assessing COVID-19 vaccine effectiveness under real-world conditions.
Such evaluations will help us understand if vaccines are performing as expected outside the more controlled setting of a clinical trial. As vaccine uptake increases nationally, we will also try to understand how well the vaccines:
- Perform in specific subpopulations
- Reduce the risk of infection (including infection without symptoms)
- Protect against milder COVID-19 illness
- Prevent more serious outcomes, including hospitalization
- Prevent spread of illness (e.g., whether people who have been vaccinated can still spread COVID-19 to others)
- Provide long-term protection (i.e., assess duration of protection)
- Protect against changes in the virus (new variants)
- Protect against COVID-19 when the vaccine is administered using a single dose or when the second dose is delayed, if these dosing regimens occur under real-world conditions
Several factors can affect real-world vaccine effectiveness, including:
- Population host factors (e.g., people not included in clinical trials who may respond differently to the vaccine)
- Virus factors (e.g., variants)
- Programmatic factors (e.g., adherence to dosing schedules or storage/handling of vaccines)
CDC will use several methods to study all of these factors, as they can all contribute different information about how a vaccine is working. Descriptions of planned evaluations CDC is conducting with partners, and, where relevant, links to protocols that detail the evaluation designs may be found below.
Select a study design below to get more information about the evaluation's name, population, outcome, protocol and participating sites.
Research on the Epidemiology of SARS-CoV-2 in Essential Response Personnel (RECOVER)pdf icon
Outcome
Symptomatic and asymptomatic SARS-CoV-2 infections
Population
Healthcare providers/first responders
Design
Prospective cohort
Participating Sites
- Baylor Scott and White Health, Temple, TX
- Kaiser Permanente Northwest, Portland, OR
- St. Luke's Hospital, Duluth, MN
- University of Arizona, Tucson, AZ
- University of Miami, Miami, FL
- University of Utah, Salt Lake City, UT
Outcome
Household transmission among healthcare workers with SARS-CoV-2
Population
Households of healthcare providers/first responders
Design
Prospective cohort
Participating Sites
- Baylor Scott and White Health, Temple, TX
- Kaiser Permanente Northwest, Portland, OR
- St. Luke's Hospital, St. Louis, MO
- University of Arizona, Tucson, AZ
- University of Miami, Miami, FL
- University of Utah, Salt Lake City, UT
Outcome
Hospitalization and severe disease with SARS-CoV-2
Population
Hospitalized adults
Design
Prospective cohort
Participating Sites
The health care organizations participating in VSD that will contribute data to this project will be confirmed soon.
Using COVID-NET and Immunization Registries to assess VE
Outcome
Hospitalization with SARS-CoV-2
Population
Hospitalized adults and children
Design
Screening method
Participating Sites
COVID-NET Sites
Outcome
Symptomatic SARS-CoV-2 infections
Population
Healthcare providers
Design
Test-negative prospective case control
Participating Sites
PREVENT Sites
- Baystate Medical Center, Springfield, MA
- Brigham and Women's Hospital, Boston, MA
- Jackson Memorial Hospital, Miami, FL
- Olive View-UCLA Medical Center, Los Angeles, CA
- Thomas Jefferson University Hospital, Philadelphia, PA
- Truman Medical Centers, Kansas City, MO
- University of Alabama Hospital, Birmingham, AL
- Community Regional Medical Center/ UCSF, Fresno, CA
- University of Chicago Medical Center, Chicago, IL
- University of Iowa Hospitals and Clinics, Iowa City, IA
- University of Massachusetts Memorial Medical Center, Worcester, MA
- LCMC Health Hospitals, New Orleans, LA
- University of Mississippi Medical Center, Jackson, MS
- University of Texas Southwestern Medical Center and Parkland Hospital, Dallas, TX
- University of Washington Hospitals, Seattle, WA
- Valleywise Health Medical Center, Phoenix, AZ.
SHEPheRD sites
- Duke University, Durham, NC
- Johns Hopkins University, Baltimore, MD
- Rush University, Chicago, IL
- University of Utah, Salt Lake City, UT
- Washington University, St. Louis, MO
- University of Wisconsin, Madison, WI
Emerging Infection Program Sites
CDC Artic Investigations Program sites
Outcome
Symptomatic infection with SARS-CoV-2
Population
Outpatient adults and children ≥6 months of age
Design
Test-negative prospective case control
Participating Sites
- Group Health Cooperative, Seattle, WA
- Marshfield Clinic Research Institute, Marshfield, WI
- University of Michigan, Ann Arbor, MI
- Henry Ford Health Systems, Detroit, MI
- University of Pittsburgh Medical Center, Pittsburgh, PA
- Scott & White Healthcare, Temple, TX