Antigen tests often fail to pick up Omicron, Munich researchers find

Researchers at Munich's Ludwig Maximilian University have found that antigen tests are often highly unreliable when it comes to detecting an infection with the Omicron variant.

Antigen tests often fail to pick up Omicron, Munich researchers find
An employee of the test center holds a corona rapid test in a corona test center in the Schiene festival hall in Saxony. Photo: dpa-Zentralbild | Sebastian Kahnert

To be 95 percent sure of picking up an Omicron infection, some of the accredited antigen tests needed a viral load up to a hundred times higher than with a Delta infection, the team led by virologist Oliver Keppler found.

A viral load is the amount of virus detectable in a patient’s body. 

Overall, eight of the nine commercially available antigen Schnelltests in the study didn’t pick up Omicron as well at the Delta variant, according results published in the journal Medical Microbiology and Immunology.

“There is tremendous heterogeneity in rapid antigen tests in terms of detecting Omicron,” Keppler said.

“On the one hand, this needs to be clearly communicated, and on the other hand, a list of usable tests needs to be published quickly,” he said.

The scientists looked at 166 cases of infection between October and January, 101 of which were with the Omicron variant and 65 of which were with Delta.

READ ALSO: What to know about Germany’s planned PCR test restrictions

They found that the least reliable tests picked up less than a third of Omicron infections with a high viral load, whereas the same type of tests picked up 70 percent of Delta infections with an equivalent viral load.

In terms of infections with a medium viral load, the tests picked up between zero and eight percent of Omicron infections and between zero and 28 percent of Delta infections.

With some 580 different antigen tests on the market, Keppler said that the Paul Ehrlich Institute – Germany’s medicines agency – should publish a list of which ones are most effective against Omicron.

“The one-eyed among the blind must now be quickly identified and published by the Paul Ehrlich Institute,” he said.

He also called on the public to exercise continued caution.

“You should never take a negative result as a free pass,” Keppler warned, adding that “asymptomatic testing with self-tests makes little sense in my view.”

He said that people should instead rely on measures such as social distancing and wearing masks, while continuing to go for testing in the case of symptoms.

SEE ALSO: German state sets out plan to end Covid tests in schools

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German doctors say Covid testing is too ‘expensive and bureaucratic’

Doctors in Germany have slammed the new Covid testing regime, which involves partly charging for rapid tests.

German doctors say Covid testing is too 'expensive and bureaucratic'

The German Health Ministry announced on Thursday that most people would have to pay a contribution rate of €3 to get a Covid rapid test, while they would remain free of charge for certain vulnerable groups.

But chairman of the National Association of Statutory Health Insurance Physicians (KBV), Andreas Gassen, called for an end to so-called Covid Bürgertests. 

“These nonsensical tests must be abolished,” Gassen told Bild newspaper. “They are far too expensive, the bureaucratic effort is huge and the epidemiological significance is zero.”

It is a “completely pointless exercise to test healthy people with (tests of) questionable quality for no reason,” Gassen said.

Gassen said, however, that PCR tests carried out on patients with symptoms are important to detect Covid infections.

If people in Germany have Covid symptoms, they can contact their GP who can arrange for a PCR test that is covered by health insurance. 

According to the new test regulation, which came into force on Thursday, the Bürgertests, which were previously free of charge for everyone, will now only be available for free to a limited extent.

READ ALSO: The new rules on getting a Covid test in Germany 

For instance, people who can’t get vaccinated for medical reasons can still get a free rapid test, as well as children up to five-years-old and some at-risk groups. 

Other people will be charged €3 per test, and under the new rules people have to state why they are getting the test.

Health Minister Karl Lauterbach said he hoped this would help combat fraud as well as cut down on the cost to the taxpayer. 

However, in a letter to Lauterbach, the heads of the 17 associations of statutory health insurance doctors said they “do not want to be responsible for making payments on invoices whose accuracy they cannot even begin to check”.

They said they “will no longer be able to bill and pay for the Bürgertests in the future”.

According to research by Spiegel, more than €1 billion was taken by fraudsters for Covid tests that never took place – or test centres that did not even exist.

READ ALSO: Germany starts charging for Covid tests 

On Thursday, Health Minister Lauterbach defended the new test regulation. He told broadcaster ZDF that he would have liked to keep the tests completely free of charge, “but we could no longer afford that”.

He said the additional bureaucratic effort for the tests is “manageable”.

Lauterbach also told RTL Direkt that the tests would now be more meaningful. “If everyone can just get tested as often as they want, without there being a reason for it, then too many tests will also be negative, or if they are positive, then often false positives.

“We have limited that so that the tests are more meaningful.”

In a tweet on Friday morning, Lauterbach said the Health Ministry was “already in constructive talks” with the the Association of Statutory Health Insurance Physician on the billing of tests. 

“The tests will remain, and will be invoiced correctly as of today,” he said, adding that they were “not pointless but help to prevent infected people from infecting others”.

A spokesperson for the Health Ministry told Bild: “The tests are not nonsensical, but save lives by breaking chains of infection. We assume that the KVs (associations) as corporations under public law, will continue to fulfil their mandate to bill and spot-check the test centres.”