RT Journal Article
SR Electronic
T1 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
JF BMJ Open
JO BMJ Open
FD British Medical Journal Publishing Group
SP e048142
DO 10.1136/bmjopen-2020-048142
VO 11
IS 6
A1 Louise J Robertson
A1 Julie S Moore
A1 Kevin Blighe
A1 Kok Yew Ng
A1 Nigel Quinn
A1 Fergal Jennings
A1 Gary Warnock
A1 Peter Sharpe
A1 Mark Clarke
A1 Kathryn Maguire
A1 Sharon Rainey
A1 Ruth K Price
A1 William P Burns
A1 Amanda M Kowalczyk
A1 Agnes Awuah
A1 Sara E McNamee
A1 Gayle E Wallace
A1 David Hunter
A1 Steve Sager
A1 Connie Chao Shern
A1 M Andrew Nesbit
A1 James A D McLaughlin
A1 Tara Moore
YR 2021
UL http://bmjopen.bmj.com/content/11/6/e048142.abstract
AB 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.Data are available on reasonable request to the corresponding author.