Digital vaccination card — Informative, safe, individual and always at hand: A concept for a vaccination certificate app that thinks along and makes regular vaccinations easier

The yellow who booklet

project info

During the Corona pandemic, an otherwise often forgotten document came back into focus: the vaccination card. It accompanies a person throughout their whole life. At the age of six weeks, every child in Germany receives the yellow who booklet, where all vaccinations are documented. According to the Robert Koch Institute’s immunisation schedule, every healthy person in Germany should be regularly vaccinated against at least thirteen diseases.

We have only realised in recent months how relieving it can be to have a little vaccine label attached to our vaccination card.
The international vaccination certificate hasn’t changed since its introduction in 1962 – but the world around it has changed rapidly.

Modern-day challenges

Complexity: Getting all your vaccinations has become far more complex. Thanks to medical advances, the number of standard vaccinations increased from five to more than thirteen in Germany. So our immunisation is getting better and better, but it’s also harder to stay on top of things.

Mobility: People today are more mobile than ever before. As a result, many people move or travel more frequently, and new diseases spread remarkably quickly.

Incompleteness: About half of the German population lacks vaccinations, although most people are actually willing to be vaccinated. Often people simply don’t have an overview of their immunisation status.

Loss of data: Losing your vaccination card is a real problem in Germany because there is no central vaccination register. If the yellow booklet remains missing, the whole vaccination documentation is usually lost.

The digital vaccination card

The vaccination card app is more than a digital backup; it helps people better understand their immunisation status and remind them about (booster) vaccinations. During my bachelor thesis, I developed a prototype for a vaccination card app that thinks along.

Knowing your vaccination status

The yellow who vaccination card is a document for experts: its language, structure and design are intended to be read by physicians. Lay people who want to understand their immunisation status quickly come up against limits. Around 43 percent of people in Germany don’t know against which diseases they’ve been vaccinated.

The vaccination card app puts an end to the rigid table structure of the who booklet and establishes a user-centered approach. People are empowered to understand their immunisation status and make informed medical decisions. Missed or pending vaccinations are highlighted and marked in colour.

Keeping an eye on your vaccination status

Every second person in Germany has an incomplete immunisation status. Prof. Dr. Betsch, who researches vaccination behaviour at the University of Erfurt in Germany, explains the lack of vaccinations: “Most people are willing to be vaccinated – but getting vaccinated is often not easy enough. Adults are also often unaware that or when they should get vaccinated.”

This is where the vaccination card app comes in with a visualisation of the immunisation status. Colour-coded circles show how long the protective effect of a vaccination is still present. Besides communicating the immunisation status, it also creates awareness that immunisation is often only temporary and needs to be boosted periodically.

Reminders ensure that people don’t miss their upcoming vaccination appointments. In addition, a short fact sheet provides low-threshold and neutral information about the different diseases. All texts are based on data from the German BZgA to ensure high-quality content.

Customised nudging

A declared goal of the vaccination card app is to motivate people to get vaccinated regularly. The vaccination card app relies on nudging, tiny behavioural impulses that positively influence people without using bans or regulations. But what influences our vaccination behaviour? What factors prevent people from getting vaccinated? How do people decide for or against a vaccination?

The nudging strategy’s core component are individualised notifications generated based on voluntary information on vaccination behaviour. The short questionnaire is based on the 5C model used in research on vaccination behaviour. It distinguishes between five influencing factors: trust in vaccinations, perception of the risk of falling ill, structural barriers, the extent of need for information and the sense of social responsibility.

Combining nudging and vaccination motivation, makes it possible to remind people to vaccinate while addressing their needs and possible fears. However, personalisation works without collecting sensitive data about individuals or using manipulative techniques.


According to a recent report, more than half of two-year-olds in Germany are missing mandatory vaccinations. How does this high figure come about? Often it is simply due to the stress of everyday life and the coordination of appointments: children should receive a total of fourteen vaccinations by the age of two. However, if the child is sick at the scheduled doctor’s appointment, it can’t be vaccinated. The vaccination has to be postponed, is then forgotten and often not caught up on.

The family function makes it easier for parents with young children to keep track of the vaccination status of the whole family. In addition to their own profile, both parents can also add their children’s profiles to the vaccination card app via an id. This helps with coordinating vaccination appointments and catching up on missed vaccinations.

From calendar to timeline

While some vaccinations protect for a lifetime, immunisation against certain diseases has to be boosted repeatedly. It’s not easy to keep track of all the vaccinations because some have to be refreshed every year (e.g. influenza), others only every ten years (e.g. measles).

Therefore, the vaccination card app therefore combines the complex immunisation schedule of the German Robert Koch Institute with the vaccinations that have already been documented to create an easier-to-understand, personalised timeline: When did I receive which vaccination? Which vaccination appointments were cancelled, and were they rescheduled?

This makes past vaccinations easier to comprehend for doctors and patients and opens up the possibility of looking into the future: based on the immunisation cycle and existing vaccinations, the timeline shows all the necessary booster vaccinations for the following years (or even your whole life).

Safe travel

More and more people are travelling to ever more remote places for business or holidays. Besides vacation photos and packed suitcases, this also means: additional travel vaccinations. But which ones exactly? And how long before departure should I take care of them? The vaccination card app now takes care of what used to involve time-consuming online research.

The vaccination card app identifies which travel vaccinations are required or recommended based on country and duration. That generates the base for a custom travel vaccination plan for your journey. Travellers are thus reminded in good time to make an appointment with their family doctor or at the local tropical institute.

Is it all just theory?

All features of the digital vaccination card are based on existing data sources and APIs. Even though the vaccination certificate app currently only exists as a prototype, the concept is designed to be as practical and feasible as possible. The goal wasn’t to build a digital pipe dream, but to demonstrate the opportunities and possibilities that lie in the user-centered digitalisation of healthcare.