The effects of monetary incentives on COVID-19 vaccination uptake

Cluster-level spillover randomized controlled trial to assess the impact of monetary incentives on COVID-19 vaccination uptake among German adults

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

ISRCTN

Registry ID

ISRCTN59503725

Enrollment

10036

Registered

2021-10-28

Start date

2021-11-10

Completion date

Unknown

Last updated

2025-02-24

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

COVID-19 (SARS-CoV-2 infection) Infections and Infestations

Interventions

Current intervention as of 04/11/2021: The study will be conducted in the city of Ravensburg, Germany. All residents of the city (age 18 years and older) will be subject to the trial. Treatment assign

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: 1. Residents of the city of Ravensburg 2. Aged 18 years or older

Exclusion criteria

Exclusion criteria: 1. The inmates of the local prison (the city’s largest address cluster) 2. Residents of the cities’ second-largest address cluster (with 75 residents)

Design outcomes

Primary

Measure	Time frame
1. Information uptake measured by whether a participant visits the informational website mentioned in the letter. The website is prominently displayed in both treatment and control letters. Each URL is unique to the individual recipient. Measured using server logs for the provided unique links from 05/11/2021 to 13/12/2021. 2. Vaccination uptake measured via an on-site record of administered vaccinations during the seven public vaccination events at 13/11/2021, 19/11/2021, 20/11/2021, 26/11/2021, 27/11/2021, 10/12/2021, and 11/12/2021	—

Measure

Time frame

1. Information uptake measured by whether a participant visits the informational website mentioned in the letter. The website is prominently displayed in both treatment and control letters. Each URL is unique to the individual recipient. Measured using server logs for the provided unique links from 05/11/2021 to 13/12/2021. 2. Vaccination uptake measured via an on-site record of administered vaccinations during the seven public vaccination events at 13/11/2021, 19/11/2021, 20/11/2021, 26/11/2021, 27/11/2021, 10/12/2021, and 11/12/2021

—

Secondary

Measure	Time frame
There are no secondary outcome measures	—

Countries

Germany

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Feb 4, 2026