Given the range of symptoms of coronavirus and the lack of distinguishing clinical features, understanding the infection prevalence is of key importance. Diagnostic tests for COVID-19 include molecular tests such as RT-PCR which are used to detect those patients with an active infection, whereas antibody tests can identify seroconversion in patients who have had prior exposure to the SARS-CoV-2 virus.
In this video, members of the team – including UoB’s Professor Alex Richter – explain the process of developing this assay.
So the Binding Site is an immunodiagnostic company. We make blood tests. We are immunologists from inception and that means that we have a great expertise in being able to manufacture highly sensitive, highly specific antibodies for the detection of diseases and for the last 35 years we have been leading in the areas in which we choose to participate – those are specific blood cancers of multiple myeloma and specific disorders of the immune system.
This sort of expertise that we’ve developed over the years has really helped us when the COVID antibody test first came out and the opportunity we saw because, quite frankly, there were other companies that were looking, we thought, for the wrong target in that disease and that’s what helped us identify the right one.
– Charles de Rohan, CEO – The Binding Site
The SARS-CoV-2 assay is a natural sort of progression for a company like us and myself to get involved in, particularly with the current pandemic. Generally during a design control process it takes around 18 months to develop an assay from concept to launch and with our collaborative partners over at the University of Birmingham, we’ve done this in around about 10 weeks – and that’s going through full verification with the design inputs on our expectations of sensitivity and specificity in a mild disease cohort.
– Dr Stephen Harding – Chief Scientific Officer
We designed an ELISA from very basic principles and the key things to get right are which part of the immune system are we looking for – i.e. which antibodies – but then very importantly what is that immune system recognising?
– Professor Alex Richter – Professor of Clinical Immunology, University of Birmingham
In the main to most antigens we make three types of antibodies IgM, IgA and IgG. IgM tends to appear first and then IgA and IgG tend to appear later. Now what we have found is that by combining M, A and G into the Binding Site assay, we’re able to pick up people earlier, we’re able to pick up people with lower levels of antibodies, and so in people who have recently been exposed there’s probably an advantage to including IgM in that assay.
Longer term after infection, IgM often drops so you have more of a reliance on picking up the IgA and IgG. The Binding Site assay is beautiful because by picking up all three, you cover all bases.
So what’s important about the spike is that it’s trimeric and this means that it takes the normal shape that you would expect the virus protein to have. This means antibodies are more likely to have a better fit for that antigen because it looks more like what it does on the surface of the virus even though we make it in cells which have never seen a virus.
– Professor Adam Cunningham – Professor of Functional Immunity, University of Birmingham
When the pandemic started I think a lot of the competitors were really keen to just get a test out on the market straight away and what we wanted to do was not to be the first to market. We wanted to be one of the better tests out there so we wanted to make sure that we had a good quality test to put on the market and I think that’s been a challenge to make sure that we’ve got it in a reasonable time frame but making sure that we’ve got a really good quality test to put out there.
– Danielle Harris, Assistant Global Product Manager
Any laboratory in the world has the capabilities of running this test and one of the things that we really wanted to do is ensure that this test would be available to everybody. I think what’s really important from a scientific point of view is that there are huge number of researchers who are absolutely committed to identifying the best assays possible to help tackle this pandemic and Binding Site are very much front and centre in that commitment.
– Dr Stephen Harding
From the get-go we’ve been committed to improving patient lives with collaboration, innovation and education. The collaboration is one-third, or one pillar of why we are where we are. We enjoy and are highly respectful of the close links and ties we have with clinicians and academics around the globe. That is why I believe they came to us with the kernel of an idea knowing that we were the experts in being able to develop, validate and verify an antibody test.
– Charles de Rohan