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During their No10 press conference on Thursday afternoon, Boris Johnson, Chris Whitty and Patrick Vallance described efforts to buy/develop an antibody/serological test.
Prof Keith Neal, Emeritus Professor of the Epidemiology of Infectious Diseases, University of Nottingham, said:
“The main role of a serological test is it will demonstrate who has already had infection with COVID-19. This will be useful in identifying people who are immune and were never tested at the time of their illness – these people will not need to re-isolate themselves when they get another respiratory infection. Another important use will be in epidemiological surveillance and modelling as it can be used to measure and monitor the spread of COVID-19 in the general population and will include those who were asymptomatic or had so minor symptoms they were missed.”
Dr Alexander Edwards, Associate Professor in Biomedical Technology, University of Reading, said:
“This is great to hear the intention to scale up testing using antibody “rapid tests”. It is absolutely possible to make very large numbers of these rapid antibody tests because the factories needed to make such diagnostic tests can scale up production rapidly, using very sophisticated ‘printers’ onto rolls of special paper. The limiting factor is time – firstly to make viral targets, and secondly to fully test them with real patient samples to be sure they give accurate data. The quickest tests may not be the most accurate, but the most skilled experts will be 100% focussed on making high quality tests. We must allow our experts to check accuracy before we can use these, and our public health system working closely with industry is critical.
“These could make a big difference – in following spread, in helping NHS workers return to work safely following self-isolation, and also in testing the new vaccines being developed. Even when available, the tests will need to be used carefully as a precious resource: as citizens we need to be patient in demanding home testing as the first priority should always be supporting vital healthcare workers and informing the big decisions being made daily to respond to this crisis.”
Prof Sheila Bird, Formerly Programme Leader, MRC Biostatistics Unit, University of Cambridge, said:
“Over the past three days, UK has conducted 20,597 antigen-tests for coronavirus-2, of which 1707 (8%) were COVID-19 positive. The relatively high positive rate is presumably because most testing in the past 3 days has been of symptomatic patients in hospitals – intensive care units, in particular. However, I should not have to be guessing how many of the these 20,000 tests were hospital-based: UK’s reporting standard should not leave me guessing!
“From my perspective, the progress that the Prime Minister announced on UK’s ongoing evaluation of the performance of a coronavirus-2 antibody test, for which a substantial order has been placed if the test credentials pass scrutiny. There are two possible test-bases: IGM as marker of recent-past infection; IGG-based as an indication of having ever-been-COVID-19-infected. (Immunoglobulin G (IgG), the most abundant type of antibody, is found in all body fluids and protects against bacterial and viral infections. Immunoglobulin M (IgM), which is found mainly in the blood and lymph fluid, is the first antibody to be made by the body to fight a new infection.) IGM gives way to IGG. Either formulation is a major step forward but they answer different questions. In modelling terms, recent-past infection tells us about “incidence”; ever-infection tells us about the prevalence of past (not very recent) infection.
“Professor Whitty also emphasised that younger adults develop symptomatic COVID-19 and may require hospitalization. Again, these messages would be more convincing if there was more transparency about the age-distribution of a) hospitalized persons who test negative VERSUS positive for COVID-19; b) quarantined healthcare workers who test negative VERSUS positive for COVID-19; c) others who test negative VERSUS positive for COVID-19. Tracking these results weekly (by sample-date) is undoubtedly highly informative about the UK’s evolution of the COVID-19 epidemic. Please share these results now for better public and professional understanding of the march of COVID-19 so that press and public can see for themselves when and where the benefits of social isolation bite.”
Comments sent out on antibody testing on Wednesday 18 March:
All our previous output on this subject can be seen at this weblink:
http://www.sciencemediacentre.org/tag/covid-19
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