Abingdonhealth.com/abc-19-response-to-media12 Nov 2020 15:24
We note the recent press speculation around the UK-RTC AbC-19TM assay and its performance. We are grateful to the authors for providing access to their data in the BMJ paper which we have reviewed.
We believe the press articles and related BMJ report puts a spotlight on the different types of antibody testing available and what their applications are, and we very much welcome this.
Our AbC-19TM IgG lateral flow assay is targeted at IgG antibodies to the full spike protein of SARS-CoV-2 (COVID19) to indicate a measure of immune response (aligned with neutralizing antibodies) and differs from other antibody tests, some of which our assay has been compared against (incorrectly in our view). Assays measuring IgM and IgG to the nucleocapsid (as used in this study) may be useful to show previous infection but have no place in understanding the levels of immunity producing antibodies (this requires measurement of IgG to Spike) as generated naturally or via vaccination.
We do have some concerns with the BMJ research report and modelling methodology, and we provide details below.
However, the Department for Health & Social Care (DHSC) reviewed in detail the Public Health England (PHE) report on the UK-RTC AbC-19TM assay prior to ordering kits and has provided the following statement:
“This report shows these tests are approved for use in surveillance studies, which is what they were purchased for.
“They were never intended for, and have never been issued for widespread public use and it is misleading and unnecessarily inflammatory to purposefully ignore this fact in the report.
“This robust evaluation was carried out by PHE at the Department’s request before any purchase was made, and PHE approved the test for use in surveillance studies.”
Our customer, DHSC, is satisfied with the performance of the test, as is the UK-RTC, and will continue to use and roll out the use of the product. Public Health England conducted an evaluation at the DHSC’s request, prior to DHSC purchasing the product and will continue to deploy the test for use in surveillance studies.
With regards to details of the report:
1. When using methods as used in previous evaluations by PHE1, results for the AbC-19TM IgG test of 92.5% sensitivity and 97.9%* specificity are in line with those other tests. (This rose to *99.2% specificity when queried samples were repeated. *This increase in sensitivity relates to 42 positives out of 1995 presumed negative samples (collected in 2016-2017) which drop to 16 positives on repeat testing).
2. An initial study2 performed at Ulster University used methods as defined by MHRA3 . Guidance from MHRA stipulated a target product profile should determine the sensitivity and specificity of antibody tests by using at least 200 samples confirmed as positive for antibodies and at least 200 samples confirmed as negative for antibodies to SARS-CoV-2. The Ulster study fulfilled this requirement and undertook a laboratory evaluation of AbC-19TM to
Sign In
Follow the stocks
