April 17, 2020

expert reaction to announcement by Roche of its new serology test for COVID-19 antibodies

The health care company Roche has announced its new serology test for COVID-19 antibodies.

Dr Robert Shorten, Chair, Microbiology Professional Committee, Association for Clinical Biochemistry and Laboratory Medicine, said:

“Antibody testing is not routinely performed to detect infections caused by respiratory viruses, such as influenza or other cold viruses. Any test that measures antibodies must be thoroughly validated to ensure that it accurately detects antibodies to SARS-CoV-2 whilst not cross-reacting with normally circulating coronaviruses. The detection of antibodies to SARS-CoV-2 does not necessarily mean that a patient is immune, and even if immunity is generated, it is not known for how long this will last. Some studies have also shown that some patients with confirmed COVID-19 infection have not produced antibodies at all. All antibody tests require expert interpretation in the context of clinical information. Validation of many antibody tests are currently underway. If these tests can be shown to work, then high capacity instruments such as this could be useful in demonstrating rates of infection at a population level.”

Prof William Irving, Professor of Virology, University of Nottingham, said:

“There is a huge need for accurate, sensitive and specific tests for antibodies to SARS-CoV-2. Negativity would indicate that an individual is susceptible to infection. Positivity would mean that the individual has been infected.

“It is difficult to say much more about the test and its efficacy, as there are no data in the announcement relating to the sensitivity and specificity of the test. One of the key worries about antibody tests is whether or not they also pick up antibodies to other human coronaviruses which have been circulating in humans as a cause of the common cold for centuries.

“We also do not necessarily know that the presence of these antibodies will signify immunity. Immunity to infection requires antibodies which are able to neutralise the virus. Not all antibodies are neutralising, and it is likely the Roche test will pick up both neutralising and non-neutralising antibodies.”

Prof Michael Hopkins, a Professor in the Science Policy Research Unit at the University of Sussex Business School with 20 years of experience studying diagnostic testing innovation, said:

“This is a helpful product to aid scale up of antibody testing. This is a test provided by Roche, a large firm that can support supply of high-throughput testing on an existing instrument available in many hospitals around the world. The question is whether Roche will have enough kit to supply the UK and all the other countries that will want these tests.

“We don’t know how effective the test will be, although Roche have a much better reputation than the suppliers of point-of-care antibody tests discussed in recent weeks. CE mark regulatory approval is a light touch regulatory framework based on self-certification. 

“It is much less likely that someone with antibodies could be reinfected, but this is a novel virus, so there is little basis for certainty. 

“This test would be very useful in helping to understand who has already had the virus (estimating its progression through the population) and this an important test for identifying people that could donate blood that could be used as a convalescent plasma (or serum) therapy that could potentially be used in treating patients severely ill with the virus.” 

Prof Babak Javid, Principle Investigator, Tsinghua University School of Medicine, Beijing and Consultant in infectious diseases at Cambridge University Hospitals, said:

“Roche doesn’t provide any information about the specifics of the test, e.g. what is the target protein of SARS-CoV2 that it uses in the test, and what is the sensitivity and specificity of the assay using validated samples (e.g. from serum of people known to have recovered from COVID-19, and from serum taken in 2019 before COVID-19).  This is important, since some antibody tests may “cross-react” with proteins from common cold coronaviruses.  Even with a test with 90% specificity, if <10% of the population has had Covid-19 but a substantial proportion have had the common cold, most of the ‘positive’ results will be “false positives” if everyone is tested.

“The test is NOT measuring “neutralizing antibody” responses, which are the strongest indirect marker of immunity to SARS-CoV2, but neutralizing antibody assays are not easy to perform and not suitable for a test aimed at testing the mass population.  To be fair, for many viral diseases, total antibody responses correlate somewhat with neutralizing antibody responses.”

Dr Al Edwards, School of Pharmacy, University of Reading, said:

“The Roche Elecsys Anti-SARS-CoV-2 serology test is indeed an important development as it will allow diagnostic laboratories with their instruments to run increasingly large numbers of antibody tests.

“Roche is not alone- there are other major diagnostics companies producing similar tests for their laboratory instruments, such as Abbott ARCHITECHT, and these seem to be being launched.

“We still need to understand what antibody test result means, but one vital tool in that process is to have as many standardised tests run with the same protocol. Hopefully these industrial tests will all produce similar results and help us to gain a more systematic understanding of antibody responses. Many of the research studies published so far show the expected pattern of antibody responses, but often each lab is using a different test protocol, making it hard to compare different studies.

“Using centralised automated immunanalyser instruments can potentially unlock larger scale population studies that use the same uniform test.

“It remains to be seen how quickly manufacturers such as Roche and Abbott can ramp up production and if we see the same test kit supply problems that have caused major delays in swab-testing for virus detection.”

Prof Eleanor Riley, Professor of Immunology and Infectious Disease, University of Edinburgh, said:

“From the look of it, this will be lab based assay for analysis of large banks of serum samples, so not suitable for home testing but potentially useful for population based studies and community testing.  And it is good news that a large pharmaceutical company, with a very good track record of producing high quality products and the capacity for mass production of test kits, thinks it has something worth rolling out. But, there are no details in the press release about the antigens used for the test or its performance (i.e. no data on sensitivity or specificity) so we can’t yet say whether this is the assay we have all been waiting for.”

Dr Simon Clarke, Associate Professor in Cellular Microbiology, University of Reading, said:

“This is a very interesting and potentially important advance in being able to diagnose who has been previously exposed to the coronavirus causing covid19, but I think the authorities in the UK would be wise to conduct independent evaluation, given how they’ve had their fingers burnt with other tests that they’ve purchased.  Moreover, this test will require space and manpower in testing laboratories in addition to equipment already made by the manufacturer.  It remains unclear how quickly laboratories that do not already have that particular instrument would be able to obtain them and at what cost.”

https://www.roche.com/media/releases/med-cor-2020-04-17.htm

All our previous output on this subject can be seen at this weblink: www.sciencemediacentre.org/tag/covid-19

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