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Every answer makes a difference.

We’re investigating how effective COVID-19 vaccines are in real life with the eCOV study. Help us out!

More participants means better findings

of 7000 participants

The eCOV study is easy, secure, and fully digital.

Just answer a few simple health questions on your phone, tablet, or computer.

Why it’s important

Our research team is working to evaluate how effective COVID-19 vaccines are in real life and to what extent tests help detect infections at an early stage. Help us get some answers to the following questions:

  • How effective are COVID-19 vaccines in everyday life?
  • How does vaccine effectiveness decline over time?
  • Do vaccinated people have different COVID-19 symptoms?
  • What are typical side effects of coronavirus vaccines?
  • When and how often are booster vaccinations necessary?

Everyone can play a part in improving testing and vaccine strategies by joining the eCOV study.

Who can participate

The eCOV study is open to anyone over the age of 18. You’re welcome to join regardless of whether or not you received a coronavirus vaccine or tested positive for COVID-19. A diverse group of participants is important to represent a large part of society in the study. More participants means better findings – every contribution counts.

What to expect

You can get started by registering with Data4Life. Once you’ve created an account, we’ll send you the initial eCOV questionnaire. It consists of 21 general health questions and only takes about 5 minutes. 

Every question you answer helps bring us closer to understanding COVID-19. We ask you to add your test results and report any symptoms in your Data4Life account for at least two months. 

Study details

Short name
eCOV study

Official name
COVID-19 study on vaccinated and unvaccinated adults

PD Dr. med. Cornelius Remschmidt, Chief Medical Officer at Data4Life

Study physician/ operational management
Nils Hohmuth

Scientific advisor
PD Dr. Rasmus Leistner

Full study information
View information for participants

Adults (18+ years old)

Browser, internet access

Ethics approval
Ethics committee of the Berlin Chamber of Physicians (Eth-11/22)


Once you join the eCOV study, you’ll gain access to charts and statistics about study participants, age groups, regions, and more.


The "COVID-19 study for vaccinated and unvaccinated adults," or eCOV study for short, aims to better understand the effectiveness of COVID-19 vaccines in everyday life.

The study is completely digital and involves answering simple health questions about COVID-19 symptoms, vaccines, side effects, and testing.

By participating, you can help researchers gain insights on COVID-19 testing and vaccines. Participation is voluntary, and every contribution counts.

The eCOV study is conducted by Data4Life and supported by the Hasso Plattner Foundation. The lead physician of the study is PD Dr. Cornelius Remschmidt, Chief Medical Officer at Data4Life.

The eCOV study is funded entirely by Data4Life, a nonprofit organization and initiative of the Hasso Plattner Foundation. Our goal is to make it easier for people to contribute to COVID-19 research.

The study is open to anyone over the age of 18.

For meaningful results, we need a good representation of the entire population. You’re welcome to participate regardless of whether or not you already had COVID-19, have been vaccinated, or have pre-existing conditions.

Study participation is purely digital. All you have to do is answer a few simple questions. You can do so using your smartphone, tablet, or computer. There are no physical requirements or appointments.

Simply create a Data4Life account here to get started.

The eCOV questions relate to both your general health and coronavirus. This includes questions about past COVID-19 infections, vaccination, side effects, and COVID-19 testing.

If you have been tested for COVID-19, please add your test results and report your symptoms in your Data4Life account.

The initial eCOV questionnaire contains a total of 21 questions. It takes no more than 5 minutes to answer. You will then be asked a few follow-up questions each week, which should only take a couple minutes.

Ideally, all participants would participate for at least 2 months. You are welcome to participate for longer and continue supporting vaccine research.

Digital studies are a simple way to do something good and contribute to research. Unlike clinical trials involving tests or physical appointments, the eCOV study requires minimal time and effort. Therefore we do not offer compensation for study participation. With just a few clicks, you can help researchers find out more about COVID-19 vaccines.

All information in your Data4Life account is private and encrypted.

Before researchers see your answers to the eCOV questions, we remove all personal identifiers (e.g. name, email address, and telephone number). This step, called pseudonymization, makes data useful for research without disclosing your identity.

You can find more information about how we maximize the security of your data here.

As soon as enough data is available, we will analyze it and publish the results in a peer reviewed journal.

Yes. The study was extensively reviewed and approved by the ethics committee of the Berlin Chamber of Physicians (Ärztekammer Berlin, Eth-11/22).

Participating for at least 8 weeks allows researchers to get a full picture and gain important insights on coronavirus infections, tests, and vaccines. If you would like to drop out earlier, you're free to do so at any time. We will do our best to take your previous answers into account.

Anyone over the age of 18 can participate in the study. This is a requirement of the ethics committee of the Berlin Chamber of Physicians (Ärztekammer Berlin). We are unable to provide access to younger participants and ask for your understanding.

If you have further questions or technical problems, please visit our help center.

Data Privacy

Your privacy matters to us, and we take a number of steps designed to safeguard your sensitive health data. All information in your Data4Life account is end-to-end encrypted and protected by two-factor authentication.

Before researchers see any answers to study questions, we remove all personal identifiers such as your name, email address, and telephone number in a process called pseudonymization.

For more information, visit our help center.

You can make a difference. Join the eCOV study today.

At Data4Life, we believe digital studies can transform the diagnosis, prevention, and treatment of diseases like COVID-19.

More participants means better findings

of 7000 participants

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