Contradicting assessments - do corona rapid tests also recognize Omikron?

Created: 01/09/2022, 4:26 PM

By: Markus Hofstetter

The rapid tests sold in Germany recognize the Omikron variant better (symbol photo) © Thomas Trutschel / photothek.de / imago

How well corona rapid tests also record the Omikron variant is still unclear.

First findings contradict each other - that's behind it:

Munich - Self-tests are an important part of combating corona.

But the explosive question arises as to whether the Omikron variant can be reliably recognized by the rapid antigen tests.

Reliability of rapid tests with the Omikron variant: findings contradict each other

There are different findings on this.

The US Food and Drug Administration (FDA) said at the end of December: "The first data indicate that antigen tests may recognize the Omikron variant, but may have a lower sensitivity." A study from Geneva also shows that some tests are carried out by Omikron are not that reliable.

The Paul Ehrlich Institute, on the other hand, assumes on the basis of the current data situation that the vast majority of the antigen tests offered in Germany and rated positively can detect an Omicron infection.

The contradicting findings can certainly be explained.

Reliability of rapid tests with the Omikron variant: Antigen tests can sometimes work worse

On the one hand, it's about the rapid test itself.

How well does it recognize the virus?

Most rapid tests identify the virus through its nucleocapsid protein.

Here too, Omikron has mutations.

“In this respect, it is possible that this antigen test sometimes works poorly, and there are also some that hardly work.

These are not the usual ones in Germany, "said Ulf Dittmer, virologist at the University of Essen, the Deutschlandfunk.

Reliability of rapid tests with the Omikron variant: lower amounts of virus in the nasopharynx can impair the result

On the other hand, it is about the amount of virus that is collected in a smear. This is where the Omikron variant differs. According to Dittmer, the viral load in the nasopharynx is lower with Omikron than with Delta. In addition, it is only noticeable over a short period of time. As a result, there is a smaller period of time in which enough viruses have built up for the test to work.

But there is also another difficulty.

"We know that antibodies that occur in humans can also have an influence on the function of the rapid antigen test," said Dittmer on Deutschlandfunk.

This means that people who have recovered also have antibodies against the nucleocapsid protein.

These antibodies could influence the rapid antigen test if the infection occurs again.

It is therefore possible that the rapid tests in those who have recovered who are infected with Omicron will not work as well.

Reliability of rapid tests with the Omikron variant: Uncertainty remains

It can therefore be assumed that rapid tests will continue to be important in the fight against the coronavirus.

But there is still uncertainty, as more corona infections can be overlooked than with the delta variant.

In contrast, PCR tests offer a more reliable way of detection.