medac is able to meet the increasing demand for urgently needed diagnostics for SARS-CoV-2 with certainty. Full complements of PCR and antibody tests are available with short delivery times.
As of now, medac has over 3 million tests available. In addition, a total of 10 million IgG tests and 7 million IgM tests will be ready for delivery in the coming weeks. medac will deliver 2 million tests to one major customer and a further 2 million to another in the coming week. Through our distribution partnership with Snibe Diagnostic, we are able to produce unlimited quantities of additional antibody tests in the coming months.
Unlimited quantities of high quality multiplex PCR tests are available immediately. Short delivery times for additional tests are guaranteed via established European manufacturer GeneProof.
medac's SARS-CoV-2 diagnostic systems are CE certified and thus meet the requirements of all applicable EU directives. CE certification is a required marking for in vitro diagnostics, allowing them to be marketed within the EU.
There is currently no gold standard against which new serological tests for SARS-CoV-2 can be aligned and validated. To date, therefore, sensitivity relates to virus detection by throat swab and PCR, and to the occurrence of clinical symptoms during the course of the disease.
However, given the diagnostic window, this is like comparing apples with pears.
This is because when the virus attacks and infects an individual, the virus’s RNA is detectable immediately. There is then a delay of a few days before the blood of infected persons generates antibodies, which form as an immune response to the infection. In the infection’s early phase, it is predominantly IgM antibodies that are produced, which then disappear as the infection resolves. Later on, IgG antibodies are generated. These have a high specificity against the virus and very likely cause immunity, at least temporarily.
The assumption that IgG antibodies indicate immunity is not confirmed and must be confirmed by further studies. Reference to clinical symptoms is only of limited value, since there are also asymptomatic cases.
It can therefore be stated that, in general, there is no diagnostic test that achieves 100 percent sensitivity or specificity. Comparable data from the manufacturers should be reviewed critically, taking into account the composition of the test group and the time of measurement.
The frequently mentioned cross-reactivity to harmless coronaviruses has not so far been demonstrated for the tests offered by medac.
PCR test results too are often difficult to compare, as they depend on the PCR method, the material used (clinical material or synthetic reference material), the equipment and extraction methods used, and the unit of measurement produced by the system. To improve PCR result comparability, WHO has defined International Units (IU) as a new standard unit of measurement for some critical parameters, such as HIV. However, there is as yet no such international standard for the novel SARS-CoV-2 virus.
To allow better comparison of PCR results and to ensure a minimum standard for the quality of the PCR tests used in diagnostics and of the laboratories carrying them out, inter-laboratory surveys using external quality assurance programs have been established for various parameters. All testing laboratories, with their respective PCR methods, must participate in these inter-laboratory comparisons at regular intervals. Since all laboratories receive the same source material with pre-set specifications that are not known to them, a certain comparability among the results is possible.
PCR quality is monitored by virtue of GeneProof's own participation in the leading German inter-laboratory survey conducted by Instand e.V. Based on material measured against standards from the Global European Virus Archive (EVAg) and with synthetic positive controls, the GeneProof SARS-CoV-2 test achieves sensitivity of up to 1.77 cp/µl. In line with WHO recommendations (Corman et al, 2020) for SARS-CoV-2-PCR tests, medac’s PCR test has a specificity of 100 percent.
The tests offered by medac are among the first tests worldwide to be awarded European CE IVD certification. Studies from Italy on these tests already exist and include comparisons with other test methods. As a result, we are able to offer quality that has been proven in practice. These tests have been used and validated by one of the largest laboratory groups in Germany and by several European countries. The data show that medac’s test is very reliable.
What sets the innovative CLIA method apart is, above all, its high accuracy and rapid results.
The modern detection method using chemiluminescence and tiny magnetic particles enables fully automated processing, generating initial results for the serological tests after only 35 minutes. In addition, samples can be loaded in a CLIA system at any time.
The ELISA method (enzyme-linked immunosorbent assay) requires the collection and joint preparation of samples, which imposes restrictions on routine laboratory processes.
In addition to the faster processing of tests, other important advantages are a larger linear measurement range for quantification and the higher sensitivity and specificity of the CLIA method.
The existence of immunity depends on neutralising antibodies, which can render the virus harmless. Neutralising antibodies bind to two specific structures of the SARS-CoV-2 virus. These structural proteins are called antigens (S and N antigens). Neutralising antibodies – against the N antigen in particular – have already been detected. It is thought that antibodies to the S antigen appear in the later stages of infection.
The avoidance of false negative tests is a critical factor in the validity of antibody tests for SARS-CoV-2. This risk can be reduced by testing for the N antigen as well as the S antigen. To achieve sufficient sensitivity, it is recommended that both antigens are used.
The test offered by medac uses both antigens: the spike glycoprotein (S antigen) and the nucleocapsid phosphoprotein (N antigen).
In contrast to other serological test procedures, medac’s CLIA test procedure measures IgM and IgG levels. For verifying the early phase of a viral infection, detection of IgM antibodies is recommended by WHO and other bodies.
IgM antibodies are generated within a few days of infection and are detectable in the blood from about 3 days after contact with the virus. A positive result for immunoglobulin M (IgM) indicates an early-phase infection, but this level drops as the infection resolves.
In the later stages of infection IgG antibodies appear. These have a high specificity against the virus (from about 5 to 7 days). IgG antibodies thus indicate a later phase of infection. It is very likely that IgG antibodies generate at least temporary immunity against SARS-CoV-2. However, this is yet to be verified by further studies.
Using medac’s antibody test, it is not only possible to determine whether someone was previously infected with the virus: the IgM value also indicates the phase of the infection at the time of testing. In this way, if acute infection is subsequently confirmed by a PCR test, virus carriers with atypical symptoms can also be detected.
In contrast, IgA antibodies provide no evidence about the time of infection, as they remain detectable in the blood even longer after the occurrence and resolution of clinical symptoms.
Both medac’s multiplex RT-PCR test and the antibody test are CE IVD certified tests carried out in accredited medical laboratories, providing stable, reliable molecular and serological evidence of an acute or recovered SARS-CoV-2 infection.
medac does not offer rapid antibody tests. The test procedure for medac’s antibody test is considerably more complex and, by using wash steps, enables the removal of the non-specific binding which would result in a false test result.
Cassette-based rapid tests for self-testing use a blood droplet to generate a result within a few minutes. The information value of a rapid test is limited by the simplicity of the test principle and should always be confirmed by other detection methods. Conclusions should not be drawn one way or the other based on the rapid test alone: a positive rapid test does not provide unequivocal detection of SARS-CoV-2 infection and a negative rapid test does not reliably exclude infection.
Previous studies of the tests offered by medac have detected no cross-reactivity with other human pathogenic coronaviruses.
For professionals: In general, however, antibody tests do not have 100 percent specificity. Non-specific reactions do not necessarily originate from related coronaviruses, but can be introduced into a test system through the production process. The antigens used are produced recombinantly, and it is these antigens that are targeted by antibodies from the blood of potentially infected individuals. Depending on the processing method, contamination may occur at this point and cause non-specific binding.
The multiplex PCR test can be used on the most common thermocyclers on the market and has already been validated for Bio-Rad and Applied Biosystems (ThermoFisher Scientific) thermocyclers and for generic systems such as the SLAN® Real-Time PCR System. Further validations, for the Roche Lightcycler 480 II for example, are planned or are being carried out at the present time. The test requires fluorescence channels FAM, HEX and Cy5.
Thanks to the universal PCR program, the SARS-CoV-2 PCR test is compatible with all other GeneProof PCR tests.
The SARS-CoV-2 antibody test (CLIA process) can only be run on Snibe Diagnostic Maglumi systems. All tests on the Maglumi systems are fully automated and are designed for maximum efficiency in routine operation.
If you suspect that you are infected with SARS-CoV-2, consult your family doctor for a laboratory test.
To check for infection, the first step is to have a swab taken from the nose, mouth or throat area. For the antibody test, a blood sample is taken.
The samples are sent to a specialised laboratory, which checks whether the sample contains the novel coronavirus.
The incubation period for SARS-CoV-2 – the time between coming into contact with the virus and the onset of symptoms – is up to 14 days. In most cases initial symptoms appear after three to five days.
The PCR test is best suited for use in the early phase of the disease, i.e. from the first day of infection until the first clinical symptoms appear. Our multiplex RT-PCR test quickly and reliably establishes whether an acute infection with SARS-CoV-2 is present (pathogen diagnosis).
The serological test for antibody detection is the method of choice once the body's immune response has begun. The antibody test uses a blood sample to detect specific antibodies that have been produced in response to SARS-CoV-2 by the immune system. These antibodies are measured in the form of immunoglobulin levels.
A positive result for the IgM test indicates an early-phase infection (from about 3 days), when the viral load is very likely to be high and the individual can potentially infect others. This can also be the case for IgG detection alone. To rule out the risk of infection with certainty, a PCR test should always be carried out in cases of positive antibody detection.
This is particularly important for individuals working in nursing, in hospitals or doctors' surgeries and for those dealing with at-risk groups in general.
If the PCR test is ordered by a physician, this counts as a suspected case and the cost is borne by health insurance providers. In the case of voluntary self-testing, the cost must be borne by the user.
It is not yet completely clear who bears the cost for antibody tests.
Your doctor will let you know as soon as the result is available. Subject to capacity in the laboratory and the transport time of the samples, a PCR test result can be available within a few hours for medically ordered PCR tests, although it usually takes up to 4 days before a result is available.
It is not yet clear how many people in Germany have already come into contact with the novel coronavirus. The number of undetected cases is high, since the infection is often mild or even goes unnoticed.
Large-scale, representative studies for the detection of antibodies can help determine how widespread the coronavirus has become in the population and also record the asymptomatic cases of people who have recovered from the virus without symptoms of illness.
Reliable epidemiological data on the extent and severity of the pandemic are a prerequisite for further prevention and intervention measures to contain the corona pandemic.
Extensive capacity in powerful, rapid test systems such as medac’s antibody tests and fully-automated Maglumi systems can speed up large-scale testing as part of determining possible immunity in Germany.
Testing for IgM antibodies also allows acutely infected and infectious virus carriers to be identified. In this way, if a PCR test subsequently confirms an active infection, virus carriers with atypical symptoms can also be detected.
The concept of herd immunity indicates that a large part of the population is permanently immune against the novel SARS-CoV-2 coronavirus – either because a vaccine has been identified or because 60 to 70 percent of the population has recovered from infection and has generated long-term neutralising antibodies.
After recovery from infection, antibodies are indeed produced, but there are as yet no reliable data as to whether the detection of antibodies can safely be equated with immunity and for how long immunity is maintained.
Immunity is achieved when neutralising antibodies are produced during the course of the infection. Existing studies indicate that the neutralising antibodies probably target the nucleocapsid (N antigen) predominantly. To date, the extent to which these antibodies are present in serum can only be tested in very complex neutralisation tests, which can only be carried out in high-security laboratories. Studies on this subject are already under way or are in preparation.
medac has reserved a total of 10 million IgG tests and 7 million IgM tests. Together with other providers in the market, the number of tests should be sufficient for Germany, Austria and Switzerland – especially since not every individual needs testing.