Rapid tests in schools: does that help?
Photo: Ronny Hartmann / dpa
It sounds like a new mantra that should lead us out of the pandemic and at least give back parts of our old life: vaccinate a lot and test a lot.
Because although the number of infections is rising slightly again, the federal and state governments are advising on Wednesday about individual easing - despite the rapidly spreading Sars-CoV-2 variant B.1.1.7.
Vaccination and testing: The federal government expects the vaccination campaign on the one hand and the massive use of rapid and self-tests on the other to cushion the effects of business openings and fewer contact restrictions and to detect infections and outbreaks in good time.
Can it work?
How do rapid tests work and how reliable are they?
Rapid antigen tests do not detect Sars-CoV-2 itself, but proteins associated with the virus.
The most important difference to the so-called gold standard PCR is that PCR tests react very sensitively and can show a positive result even with a low concentration of viruses.
Antigen tests, on the other hand, require a large amount of viruses, so they often only work if a person is very infectious and the sample has been taken correctly.
The rapid tests show a result on a test strip provided for this purpose within 15 minutes, similar to a pregnancy test.
The sample does not have to be sent to the laboratory for evaluation.
However, due to the lower reliability of rapid tests, a PCR test must also be carried out if the result is positive.
An overview study, which was initially published as a preprint, i.e. not yet checked by independent experts, found that the rapid antigen tests available to date, if used correctly, detect an average of at least 88 percent of infections in the first week after the onset of symptoms.
However, a person infected with Sars-CoV-2 is usually highly contagious even before the onset of symptoms.
Still, the scientists emphasize that the rapid antigen tests can be an effective tool in pandemic control, as they still detect the majority of positive cases.
Where can I get a quick test from?
So far, these tests have only been approved for professional use by trained personnel, as a nasopharynx swab usually has to be taken.
They were mainly used in nursing homes or hospitals.
They are now also used in schools and companies - the prerequisite is that the staff have been trained.
The federal and state governments are now discussing the strategic implementation of a new test strategy.
Companies should, for example, provide their employees with a free quick test every week, according to a draft resolution.
Starting next week, all asymptomatic citizens should also be able to have a corona rapid test carried out free of charge at least once a week in a test center, a doctor's practice or pharmacy.
The federal government wants to bear the costs for this (around 18 euros are estimated per rapid test).
One problem with this is that the rapid tests are not yet available in sufficient quantities.
What about the home self-tests?
Just last week, corona self-tests for use by laypeople were approved for the first time in Germany.
The Federal Institute for Drugs and Medical Devices (BfArM) has now issued special approvals for six products;
They are expected to be available in drugstores from March 9th.
In the self-administered tests, the samples are taken through a swab in the anterior nasal area.
This can be done safely by laypeople.
Gargle and saliva tests are also being developed.
One problem with home self-tests is that a positive test result must be confirmed by a PCR test.
This means that after a positive self-test, citizens must act independently, isolate themselves immediately and make an appointment by telephone with their family doctor or in a test center.
All contact persons from the past few days should also be informed as soon as possible.
Since a positive self-test is not automatically reported to the health department, this cannot be checked.
The quarantine can also only be officially ordered when the health department learns of the infection.
Critics also criticize the fact that people with a negative rapid test result could feel a false sense of security.
"It should be clear to everyone that the test results are only a snapshot," said Medical President Klaus Reinhardt, who called for clear and easily understandable information for the responsible use of self-tests.
Even with a negative test result, distance, mask protection and hygiene rules must be observed.
Nevertheless, the self-tests are another means that can help contain infection: because they reliably find highly contagious people.
If you regularly test yourself at home and isolate yourself immediately if the test result is positive, you can make a significant contribution to effectively containing the pandemic - also because you can avoid contact with others, for example with medical staff or fellow travelers on the train journey to the test center.
In addition, self-tests ensure speed: So far, it has taken an average of four days for an infected person to come into contact with the health department for the first time.
Four days in which one person could potentially infect others.
One reason for this is that many often wait a day or two before going to the doctor and getting tested.
The hurdle of doing a corona test and isolating yourself immediately if the result is positive is less if the test is next to the toothbrush cup and costs little or nothing.
Contacts can be informed more quickly and chains of infection can be interrupted more quickly.
Even if the rapid tests cannot reliably find all infectious people, that is still better than not finding any.
Where can I buy the home tests and how expensive are they?
The rapid antigen tests for use at home could soon be widely available in drugstores and supermarkets.
The drugstore chains Rossmann and dm expect the tests to be available in their stores from March 9th.
Supermarkets have not yet given a specific date.
The tests should also be available in pharmacies.
However, since there will probably not be enough tests in the beginning, there will probably be a delivery restriction initially.
No company has yet given any specific information on how expensive the self-tests could be.
Federal Minister of Health Jens Spahn originally spoke of a one euro deductible.
The home tests have long been available in other countries.
In Germany, there are minimum criteria that rapid tests must meet in order for the federal government to cover their costs.
The BfArM is currently reviewing many tests and keeping a list of relevant products.
These are independently checked by the Paul Ehrlich Institute (PEI).
What can the new test strategy do and what cannot?
Most experts agree: Rapid tests cannot replace PCR tests, but they can complement them.
Because with the uncomplicated and cheaper procedure you could reach people who do not want to or cannot be tested so far - either because the effort is too high for them, the result takes too long or a voluntary test of asymptomatic people is currently not covered by the health insurance .
If rapid tests are used frequently, about twice a week, the likelihood of finding positive cases increases.
The increased frequency of tests and their rapid results could then compensate for the fact that the antigen tests are less sensitive than PCR tests.
Some countries and regions such as Austria or South Tyrol have been testing the widespread use of rapid tests for months.
In Austria, where lessons have been running again since the beginning of February, 1,500 infected schoolchildren have been found by rapid tests since then, who otherwise might have gone undetected.
According to the Austrian Ministry of Education, these are immediately isolated and tested using PCR.
In the country there are also many ways to get tested free of charge.
The government is betting on facing the pandemic without further lockdowns.
However, the seven-day incidence is currently well above the German one.
South Tyrol, on the other hand, was unable to counteract the easing with rapid tests: the northern Italian region had to impose a very tough lockdown with curfew last month because the mutation B.1.1.7 is circulating and the number of cases has skyrocketed - despite the massive use of rapid tests.
The examples show how important it is to clearly communicate the advantages and disadvantages of rapid tests: False-negative results could lead to people being more careless and no longer complying with the hygiene measures even though they are actually infected.
False-positive results, on the other hand, can mean that people isolate themselves unnecessarily - but only until the result has been verified by a PCR test.
The message should therefore be: rapid tests are better than not testing at all, and the more often you test yourself, the more reliable the result.
Anyone who has a negative rapid test result can visit their grandparents with a mask and distance.
Anyone who has a positive result must isolate themselves immediately, inform their contacts and do a PCR test.
Icon: The mirror
With material from AFP and dpa