Evaluation of the IgG antibody response to SARS CoV-2 infection and performance of a lateral flow immunoassay: cross-sectional and longitudinal analysis over 11 months
David Hunter,
Peter Sharpe,
Louise J Robertson,
Julie S Moore,
Kevin Blighe,
Kok Yew Ng,
Nigel Quinn,
Fergal Jennings,
Gary Warnock,
Mark Clarke,
Kathryn Maguire,
Sharon Rainey,
Ruth K Price,
William P Burns,
Amanda M Kowalczyk,
Agnes Awuah,
Sara E McNamee,
Gayle E Wallace,
Steve Sager,
Connie Chao Shern,
M Andrew Nesbit,
James A D McLaughlin,
Tara Moore
Affiliations
David Hunter
2Belfast City Hospital, Belfast, UK
Peter Sharpe
Clinical Biochemistry Laboratory, Southern Health and Social Care Trust, Portadown, UK
Louise J Robertson
Biomedical Sciences Research Institute, Ulster University, Coleraine, UK
Julie S Moore
Biomedical Sciences Research Institute, Ulster University, Coleraine, UK
Kevin Blighe
Biomedical Sciences Research Institute, Ulster University, Coleraine, UK
Kok Yew Ng
Nanotechnology and Integrated Bioengineering Centre, Ulster University—Jordanstown Campus, Newtownabbey, UK
Nigel Quinn
Clinical Biochemistry Laboratory, Southern Health and Social Care Trust, Portadown, UK
Fergal Jennings
Clinical Biochemistry Laboratory, Southern Health and Social Care Trust, Portadown, UK
Gary Warnock
Microbiology Laboratory, Southern Health and Social Care Trust, Portadown, UK
Mark Clarke
Northern Ireland Blood Transfusion Service, Belfast City Hospital, Belfast, UK
Kathryn Maguire
Northern Ireland Blood Transfusion Service, Belfast City Hospital, Belfast, UK
Sharon Rainey
Northern Ireland Blood Transfusion Service, Belfast City Hospital, Belfast, UK
Ruth K Price
Biomedical Sciences Research Institute, Ulster University, Coleraine, UK
William P Burns
Nanotechnology and Integrated Bioengineering Centre, Ulster University—Jordanstown Campus, Newtownabbey, UK
Amanda M Kowalczyk
Biomedical Sciences Research Institute, Ulster University, Coleraine, UK
Agnes Awuah
Biomedical Sciences Research Institute, Ulster University, Coleraine, UK
Sara E McNamee
Nanotechnology and Integrated Bioengineering Centre, Ulster University—Jordanstown Campus, Newtownabbey, UK
Gayle E Wallace
Royal Victoria Hospital, Belfast Health and Social Care Trust, Belfast, UK
Steve Sager
Biomedical Sciences Research Institute, Ulster University, Coleraine, UK
Connie Chao Shern
R&D, Avellino Labs USA, Menlo Park, California, USA
M Andrew Nesbit
Biomedical Sciences Research Institute, Ulster University, Coleraine, UK
James A D McLaughlin
Nanotechnology and Integrated Bioengineering Centre, Ulster University—Jordanstown Campus, Newtownabbey, UK
Tara Moore
Biomedical Sciences Research Institute, Ulster University, Coleraine, UK
Objective To evaluate the dynamics and longevity of the humoral immune response to SARS-CoV-2 infection and assess the performance of professional use of the UK-RTC AbC-19 Rapid Test lateral flow immunoassay (LFIA) for the target condition of SARS-CoV-2 spike protein IgG antibodies.Design Nationwide serological study.Setting Northern Ireland, UK, May 2020–February 2021.Participants Plasma samples were collected from a diverse cohort of individuals from the general public (n=279), Northern Ireland healthcare workers (n=195), pre-pandemic blood donations and research studies (n=223) and through a convalescent plasma programme (n=183). Plasma donors (n=101) were followed with sequential samples over 11 months post-symptom onset.Main outcome measures SARS-CoV-2 antibody levels in plasma samples using Roche Elecsys Anti-SARS-CoV-2 IgG/IgA/IgM, Abbott SARS-CoV-2 IgG and EuroImmun IgG SARS-CoV-2 ELISA immunoassays over time. UK-RTC AbC-19 LFIA sensitivity and specificity, estimated using a three-reference standard system to establish a characterised panel of 330 positive and 488 negative SARS-CoV-2 IgG samples.Results We detected persistence of SARS-CoV-2 IgG antibodies for up to 10 months post-infection, across a minimum of two laboratory immunoassays. On the known positive cohort, the UK-RTC AbC-19 LFIA showed a sensitivity of 97.58% (95.28% to 98.95%) and on known negatives, showed specificity of 99.59% (98.53 % to 99.95%).Conclusions Through comprehensive analysis of a cohort of pre-pandemic and pandemic individuals, we show detectable levels of IgG antibodies, lasting over 46 weeks when assessed by EuroImmun ELISA, providing insight to antibody levels at later time points post-infection. We show good laboratory validation performance metrics for the AbC-19 rapid test for SARS-CoV-2 spike protein IgG antibody detection in a laboratory-based setting.
