Independent directory Public ClinicalTrials.gov records United States
ClinicalTrials.gov record
Completed Not applicable Interventional Results available

COVID-19 Vaccinations With a Sweepstakes

ClinicalTrials.gov ID: NCT04951310

Public ClinicalTrials.gov record NCT04951310. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.

ClinicalTrials.gov public records Last synced Sep 4, 2026, 5:45 PM EDT

Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.

Brief summary

Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.

To reach herd immunity for COVID-19, experts estimate that 70% of the population will need to be vaccinated. However, vaccination rates have begun to slow down in the United States. The investigators will partner with Philadelphia to launch a COVID-19 vaccination sweepstakes, in which residents will be eligible to win if they have received at least one dose of the COVID-19 vaccine prior to a given drawing. Drawings will be held every two weeks; multiple prizes of various sizes will be awarded in each drawing. Half of the prizes in each size category in each drawing will be awarded to residents of a zip code that is randomly selected from a pre-defined list of under-vaccinated zip codes (this zip code will be announced at the start of each 2-week drawing period), the other half will be awarded to residents outside of that selected zip code. The investigators will analyze vaccination rates in Philadelphia as compared with neighboring regions before, during, and after the specified time period, as well as analyze vaccination rates in the three selected zip codes compared to the other zip codes that could have been targeted (the residual set of under-vaccinated zip codes) to determine the effectiveness of the sweepstakes at encouraging vaccinations.

Study identification

NCT ID
NCT04951310
Recruitment status
Completed
Study type
Interventional
Phase
Not applicable
Lead sponsor
University of Pennsylvania
Other
Enrollment
3,827,656 participants

Conditions and interventions

Conditions

Interventions

Behavioral

Eligibility (public fields only)

Age range
18 Years and older
Sex
All
Healthy volunteers
Healthy volunteers not accepted

This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.

Study timeline

Start date
Jun 6, 2021
Primary completion
Aug 13, 2021
Completion
Aug 13, 2021
Last update posted
Feb 2, 2025

2021

United States locations

U.S. sites
1
U.S. states
1
U.S. cities
1
Facility City State ZIP Site status
University of Pennsylvania Philadelphia Pennsylvania 19104

Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.

About this trial record page

What this page shows
Public field values for ClinicalTrials.gov record NCT04951310, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
What this page does not do
No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
Where the data comes from
Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
Last refresh
Last update posted Feb 2, 2025 · Synced Sep 4, 2026

Related: full search, browse by condition, browse by drug or therapy, browse by sponsor, browse by U.S. city.

Open the official record

The complete protocol, eligibility criteria, and contact information for NCT04951310 live on ClinicalTrials.gov.

View official ClinicalTrials.gov record →