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expert reaction to the announcements made at the no.10 press conference on Wednesday 18th March

Reaction to the announcements made at the no.10 press conference on Wednesday 18th March.


Dr Alexander Edwards, Associate Professor in Biomedical Technology, University of Reading, said: 

“During virus infection (e.g. SARS-CoV2 virus causing COVID-19 disease) very specific and sensitive tests for the viral genome can detect as little as one virus particle using a technique called RT-PCR. However, during patient recovery the virus is eliminated and such tests can no longer tell who has been infected. This creates significant uncertainty especially if someone has self-isolated due to mild and unclear symptoms. There is a big worry that NHS workers will self-isolate and not be tested, and they will not know if they are safe to return to work.


“There is a complementary type of test that measures the antibody responses to virus in blood serum. Antibody takes a few weeks to develop against a new infection, but then lasts for much longer in the bloodstream than the original virus, providing a historical picture of past infections. This type of “serology” testing is powerful tool used for example to check if vaccines work, or to find out if people have encountered an infection. For other infections, these tests start to give positive results around 7 days after infection, and can stay positive for weeks, months or even years.

“There are challenges in developing antibody tests. Unlike RT-PCR that can be developed very quickly, antibody tests take time to refine, and require production of viral components that have to be purified and standardised. Laboratory antibody methods are quite slow and labour-intensive, so rapid tests – like pregnancy testers- are very attractive, but these typically have less accuracy than lab methods. Rapid tests are quick to manufacture but have to be carefully designed and validated, which is why they are not approved for use and we haven’t seen widespread use yet. As with vaccines, it’s absolutely vital that any test is accurate and safe, and that takes time. There are some rapid tests already on the market, but without being properly tested and validated, these are not safe to use and can give false results. Having said that, they probably work to some extent, so could potentially be combined with other methods usefully.

“The limitation with current rapid tests is why many research groups – such as our own at University of Reading – have worked hard to develop novel blood testing technology that allows multiple laboratory tests to be performed in a small, portable and rapid device, without needing lab equipment. I hope that the current urgent need will drive rapid uptake of such innovative cutting edge technology, alongside making best use of tried-and-tested laboratory methods.”


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


“The news that advances have been made in a developing a serological test for the coronavirus that causes Covid-19, is encouraging.  This will allow for better analysis of who within the population has previously had the infection and allow mathematical modellers to better analyse how the virus spreads in the population.  In the absence of a vaccine, this is essential for the development of better control measures. 

“The two remaining hurdles will be the scaling up of tests for use across the population and making testing easier and cheaper to be used widely which is where innovative solutions using existing technologies may be able to help. If the Government is able to clear both of those challenges, we could see an army of people who have cleared the virus and developed antibodies back on our streets, in our hospitals and schools to help the UK deal with the pandemic.”


Dr Andrew Freedman, Reader in Infectious Diseases, Honorary Consultant Physician, Cardiff University School of Medicine, said:

“The planned increase in testing to 25,000 per day in England is welcome news.  Currently testing is being limited mainly to those patients ill enough to require admission to hospital.  However, the increased testing capacity should allow more patients to be tested in the community.  This will enable surveillance of the spread of the infection within the community, as well as informing individuals with symptoms whether or not they have COVID-19 and whether they need to continue to self-isolate.  This is particularly important for healthcare workers and others who provide essential services.

“The large increase in confirmed cases as well as deaths in the UK today is very concerning, particularly as the bulk of these new diagnoses are in patients sick enough to need admission to hospital.”


Prof Sheila Bird, Formerly Programme Leader,  MRC Biostatistics Unit, University of Cambridge, said:

“Tremendously exciting news from Sir Patrick Vallance that, sooner rather than later, UK may have an antibody test by which we can monitor the proportion of population that has developed antibody against coronavirus-2.

“In the meantime, monitoring relies on antigen testing. Deployment of tests has changed fundamentally – more than once.

“But UK’s public reporting standard pretends ignorance of the context in which testing has occurred. Far from being in ignorance, those monitoring the evolution of the COVID-19 pandemic quintessentially need to heed the context of testing. And do so.

“Hence, please, let us improve dramatically the reporting standard that UK offers publicly – by sample-week and test-route simultaneously. In January there was a dearth of testing in hospitals because our effort was then directed at contact tracing of imported cases to close off each incursion; by mid-March, as the epidemic progressed, a substantial part of our test-capacity is directed at hospitalized patients with pneumonia (the more seriously affected) so that a higher proportion of tests would be expected to be positive: due to the change of context for testing in addition to epidemic progression.

“For example, by 14 February 2020, we had nine COVID-19 positives out of 2,964 tested (3 per 1000); between 15th and 29th February, a further 14 COVID-19 positives were reported (1.9 per 1000) out of 7,519 tested (community surveillance added); between 1st and 14th March, UK announced a further 1,117 COVID-19 positives (41 per 1000) out of 27,263 tested. These three rates are not comparable because they are based on a substantially different mixture of test-routes which confounds our impression of how sharply cases are increasing. Soon, healthcare workers will be preferentially tested in symptomatic.

“It is thus high time that the UK unscrambled its reporting of COVID-19 testing to date (please, report by sample-week and test-route). Doing so allows insightful appraisal of UK’s test-data by professionals, press and the public, and support better the public’s understanding of how the COVID-19 pandemic is evolving.


Prof Stephen Reicher, Wardlaw Professor of Psychology, University of St. Andrews, said:

“The clear issue with all these distancing measures is compliance. If people continue to go out and mix, the measures won’t have their full effect. And the danger is that, with schools closed, young people (who are least affected by the virus) might think that the sacrifices involved in staying in are not worth-while. So it is crucial to be clear that everyone understands that this is about how we get through this as a community and that anyone who ignores distancing advice is putting their community – especially the most vulnerable in their community – at risk. Moreover, – as every teacher will know – the most effective tool for dealing with those who do continue to act selfishly – is to use the disapproval of the community against them. A strong sense of community, and building strong community norms are the best resource we have for dealing with this crisis.”


Dr Rupert Beale, Group Leader, Cell Biology of Infection Laboratory, Francis Crick Institute, said:

“The increased testing capacity is extremely important. Hopefully this will enable healthcare workers who may have symptoms to be tested. I hope that this is increased much further in the next few days and weeks, it’s clearly a crucial part of an effective response to the pandemic.”


Dr Bharat Pankhania, Senior Clinical Lecturer, University of Exeter Medical School, said:

“I welcome the increase in testing of coronavirus Covid-19 in the community. As a priority, it’s very important to test, and identify and isolate cases and their contacts. Testing should particularly be prioritised for healthcare workers.

“I’m concerned about the impact of school absences and school closures. I suggest that we urgently test for Covid-19 presence or absence presence and close those where it is present, rather than closing all schools.” 


All our previous output on this subject can be seen at this weblink:


Declared interests

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