For the first time this week, Germany’s Federal Institute for Drugs and Medical Devices (BfArM) approved three rapid coronavirus tests for home use. Here’s everything you need to know about the tests - sometimes also known as rapid antigen tests - including how they work, how accurate they are, and how you can get your hands on one in Germany. 

Which rapid tests have been approved?

Since the beginning of February, the BfArM has received applications for special approval from the manufacturers of around 50 rapid coronavirus tests. Three have now been given the go-ahead to begin selling in Germany. 

It is expected that more tests will be given approval over the next couple of weeks, meaning shelves in Germany should soon be well-stocked with plenty of home testing kits. 

Where can I get a rapid COVID-19 test in Germany?

Federal Health Minister Jens Spahn told ARD that the tests should be accessible to all, and that they will start appearing in shops within the next few days. Now that they’ve been approved for home use, they can be sold virtually everywhere: not only in pharmacies and drugstores but also in supermarkets and corner shops, as well as on the internet. 

How much does an at-home corona test cost?

A price for the end consumer has not yet been determined, but it depends heavily on two factors: firstly, how many other rapid tests receive approval over the coming weeks, as competition should quickly reduce prices. Current estimates suggest that each test will cost less than 10 euros - but it is also conceivable that the government will step in to lower the price through state aid. 

One thing is for certain: Jens Spahn’s original plan to offer the tests for just one euro each are currently off the table. The minister now wants to wait and see how prices develop on the market. Whether or not the government intervenes to make self-tests available to everyone depends on whether the price settles at “1,99 euros or 8,99 euros,” said Spahn. 

How do rapid coronavirus tests work?

Rapid coronavirus tests work on the same principle as other kinds of swab tests - by detecting components of COVID-19 in a sample. The advantage is that the swab can be taken in the anterior (front) nasal region, and can thus easily be carried out at home. 

The test kit consists of a long, thin brush, a bottle of sterile “buffer solution”, and a test strip. The brush is used to take a sample from the mucus membrane in the nose (by inserting it a few centimetres into one nostril and “twizzling” it around). The sample is then diluted with the liquid solution, and a few drops are dripped onto the test strip. 

If the sample contains sufficient quantities of the antigen, it binds to specific antibodies in the solution and uses pigments to create a thin line in the viewing window of the test strip - similar to a pregnancy test. The result is usually available within 15 to 20 minutes. 

Some other rapid tests take samples from the mouth - for instance with a swab, or by having the patient gargle a solution - but these kinds have not yet received approval in Germany. 

How accurate are rapid COVID tests?

When talking about “accuracy” of COVID-19 tests, it’s important to differentiate between “accuracy” and “sensitivity”. Rapid tests are only effective at detecting high viral loads. This means that, if a sample contains sufficient quantities of coronavirus antigens, rapid tests are fairly accurate. 

But where they fall down is on the sensitivity front. Unlike PCR tests, rapid tests do not amplify the virus, and therefore they often miss lower levels of infections. This means that they can give false negative results to people who are, for example, in the early or latter stages of an infection, or those who are symptomless.

This all also assumes that the test has been used correctly - and this is an issue that can’t be controlled with home testing kits. Typical errors could include taking samples from the wrong place (too low down in the nasal cavity), applying too few drops of the liquid, or reading the result incorrectly.

Before issuing its approval, the BfArM therefore wanted to make sure that the tests were not only accurate, but also easy and safe to use for lay people (rather than medical professionals). This included making sure the instructions are easy to understand. 

What does a negative result mean?

A negative test result means that there is a very high probability that the person is currently not contagious. However, it does not mean that the person isn’t infected - and that they can’t go on to infect others the next day. It’s important to think of rapid tests as a snapshot result. 

According to the Robert Koch Institute (RKI), it is still necessary to adhere to distance and hygiene rules, even if you have received a negative rapid test result. If you have symptoms, you should continue to self-isolate. 

If, on the other hand, the result is positive, you should immediately contact your doctor or local health department to arrange a PCR test, and self-isolate until your test can be taken. According to the RKI, a positive result initially only represents a suspicion of infection, not a firm diagnosis.