Semi-Quantitative COVID-19 IgG Antibody Rapid Test now available for use by professionals or trained lay-users

York, U.K. 16th December 2021: Abingdon Health plc (AIM: ABDX), a leading international developer and manufacturer of high quality and effective rapid tests, announces the commercial launch and UKCA and CE-marking of AbC-19™ Semi-Q Rapid Test, a lateral flow test that detects the presence of IgG neutralising antibodies to the full trimeric spike protein of the SARS-CoV-2 virus and produces semi-quantitative results via a line intensity scorecard. The product was initially launched for research purposes in September 2021.

AbC-19™ Semi-Q Rapid Test is available for use by professionals or trained lay-users, meaning government agencies, pharmacists, testing centres or workplaces can use the test to identify and monitor a person’s level of antibody-based protection to COVID-19.

The presence and strength of IgG neutralising antibodies following infection and/or vaccination is a key indicator of an individual’s protective immune response to COVID-19. The intensity of the line on the scorecard, which can be seen visually, is proportional to the number of IgG antibodies present in the finger-prick blood sample, with higher levels of antibodies producing a stronger test line.

The scorecard used for AbC-19™ Semi-Q Rapid Test has been referred to in studies, including one from the University of Birmingham, showing the test line response to be proportional to the number of antibodies in an international standard.1,2

Data gathered during the validation of AbC-19™ Semi-Q Rapid Test confirmed antibody responses to vaccination and infection differ from person to person. Each participant in our validation study was tested weekly prior to and post vaccination. The data highlighted that the antibody response to first, second and booster vaccines varied considerably and that the change in antibody levels over time also varied by individual. For example, some participants maintained some level of IgG antibodies beyond 20 weeks post second immunisation, whilst others showed a steeper decline. These differences in immune response were also seen across one familial household. This has significant implications for the individual, but also for governments with regards to monitoring the impact of vaccine programmes.

3 graphs showing COVID IgG antibodies waning after vaccination

Graphs from the study can be seen here.

This data, in addition to conclusions made in other studies, emphasises the importance of understanding antibody levels in making informed decisions about when someone’s protection levels have decreased. Recently, Pfizer announced that early studies indicate that robust protection against the Omicron variant could be achieved through a third dose of vaccine as this increases the antibody titres by 25-fold.3

Recent research has also highlighted immuno-compromised individuals generate lower levels of antibodies compared with healthier people following two vaccine doses,4 and that there are variations in vaccine-response between males and females.5 A further study highlighted different responses in patient cohorts when comparing the Moderna and Pfizer-BioNTech vaccines,6 with one study noting antibody levels start to reduce at around 2-3 months after two vaccine doses.7

Determining the presence and strength of IgG neutralising antibodies enables governments to guide on vaccine deployment to the most vulnerable. For workplaces, understanding who is most at risk helps to shape return-to-work or health and safety policies. The validation of vaccine certificates with antibody testing, for borders or large/crowded events, could help to determine risk levels for individuals. In countries with lower vaccine supply, IgG neutralising antibody testing could be deployed to stratify the population and direct vaccines to those with no or limited protection to the SARS-CoV-2 virus.

Chris Yates, Chief Executive Officer of Abingdon Health, commented:

“Some countries are currently experiencing a fourth wave of COVID-19 and it is critical that we are able to accurately monitor our antibody levels to determine if and when we need booster vaccine doses. Our own research, as well as other published data, shows that there is a significant degree of variability between individuals in their antibody levels, following infection and/or vaccination. On an individual level we believe there is an increasing need to know your antibody status as this will allow all of us to manage their own behaviour in light of own specific levels of immunity.

“Our AbC-19™ Semi-Q Rapid Test uses the full trimeric spike protein of the SARS-CoV-2 virus to capture COVID-19 IgG antibodies so we would expect the polyclonal response, seen following either vaccination or infection with different variants, to produce antibodies which are detected. However, the important message from healthcare agencies is that high levels of antibodies, as seen following booster vaccinations, will help fight variants such as Omicron. This is important as antibody levels will wane over time. Being able to monitor and track antibody levels using the AbC-19™ Semi-Q Rapid Test provides this information to give another tool in our anti-COVID-19 toolbox.

“As research works towards achieving a globally recognised standard for antibody thresholds, tools such as the AbC-19™ Semi-Q Rapid Test allow individuals, workplaces, and governments to assess risk based on evidence of someone’s level of protective immune response. Doing so provides a means to implement appropriate and specific interventions or policies, at an individual or community level, rather than imposing blanket lockdowns.”


To read more about AbC-19TM Semi-Q Rapid Test visit:




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About Abingdon Health

Abingdon Health is a world leading developer and manufacturer of high-quality rapid tests across all industry sectors, including healthcare and COVID-19. Abingdon is the partner of choice for a growing global customer base and takes projects from initial concept through to routine and large-scale manufacturing and has also developed and marketed its own labelled tests.

The Company offers lateral flow product development, regulatory support, technology transfer and manufacturing services for customers looking to develop new assays or transfer existing laboratory-based assays to a lateral flow format. Abingdon Health aims to support the increase in need for rapid results across many industries and locations and produces lateral flow tests in areas such as infectious disease, clinical testing including companion diagnostics, animal health and environmental testing. Faster access to results allows for rapid decision making, targeted intervention and can support better outcomes. This ability has a significant role to play in improving life across the world. To support this aim Abingdon Health has also developed AppDx®, a customisable image capturing technology that transforms a smartphone into a self-sufficient, standalone lateral-flow reader.

Founded in 2008, Abingdon Health is headquartered in York, England.