It is all based on a proven method. The new thing is that it has been found where the body's immune system attacks the virus. It involves using antibodies that are formed in the blood once you become infected and that remain long after the virus has disappeared. 

- This disease is so new that we do not know for sure how strong antibody and immune responses you get to the virus. Especially not if you become mildly ill or have symptoms, says Mattias Forssell, immunologist and associate professor at Umeå University.

Can explore the herd immunity

The test can in principle begin to be used to see if healthcare professionals working with risk groups have become immune. It will also be possible to explore how far the flock immunity has reached in the population. 

- We know the majority of patients who end up in hospitals develop antibodies. Other studies have also shown this. But some patients do not develop antibodies, although they are few, says Mattias Forsell. 

Tegnell was asked about the Umeå research 

The test is evaluated for research purposes. It will now be evaluated by Laboratory Medicine and Clinical Microbiology at Norrland University Hospital and adapted to the business.  

But which tests to use and which to test is a political decision. At Monday's press conference, city epidemiologist Anders Tegnell was asked how he stands for the research done in Umeå.

- There are a number of players who are doing antibody tests. We will see who ultimately has the best quality to discern who is immune and not. So far we have too little data, Anders Tegnell said. 

In the clip above you will see how the test works. You can see the entire report in Ask the Doctor on SVT Play.