Abstract
Background: Antibody waning after SARS-CoV-2 infection may result in reduction in long-term immunity following natural infection and vaccination, and is therefore a major public health issue. We undertook prospective serosurveillance in a large cohort of healthy adults from the start of the epidemic in England.
Methods: Clinical and non-clinical healthcare workers were recruited across three English regions and tested monthly from March to November 2020 for SARS-CoV-2 spike (S) protein and nucleoprotein (N) antibodies using five different immunoassays. In positive individuals, antibody responses and long-term trends were modelled using mixed effects regression.
Findings: In total, 2246 individuals attended 12,247 visits and 264 were seropositive in ≥ 2 assays. Most seroconversions occurred between March and April 2020. The assays showed > 85% agreement for ever-positivity, although this changed markedly over time. Antibodies were detected earlier with Abbott (N) but declined rapidly thereafter. With the EuroImmun (S) and receptor-binding domain (RBD) assays, responses increased for 4 weeks then fell until week 12-16 before stabilising. For Roche (N), responses increased until 8 weeks, stabilised, then declined, but most remained above the positive threshold. For Roche (S), responses continued to climb over the full 24 weeks, with no sero-reversions. Predicted proportions sero-reverting after 52 weeks were 100% for Abbott, 59% (95% credible interval 50-68%) Euroimmun, 41% (30-52%) RBD, 10% (8-14%) Roche (N) < 2% Roche (S).
Interpretation: Trends in SARS-CoV-2 antibodies following infection are highly dependent on the assay used. Ongoing serosurveillance using multiple assays is critical for monitoring the course and long-term progression of SARS-CoV-2 antibodies.
【초록키워드】 public health, vaccination, Immunity, antibody, SARS-COV-2 infection, Antibody Response, Infection, progression, healthcare worker, immunoassays, Protein, Antibody responses, Region, Seroconversion, SARS-CoV-2 antibodies, SARS-CoV-2 antibody, RBD, clinical, response, large cohort, nucleoprotein, trend, threshold, natural infection, Roche, England, Euroimmun, Critical, seropositive, SARS-CoV-2 spike, Abbott, credible interval, individual, domain, positive, positive individuals, MOST, Effect, FIVE, English, the epidemic, Course, tested, occurred, proportion, healthy, recruited, assays, remained, dependent on, changed, reduction in, declined, 【제목키워드】 public health, Antibody Response, Cohort, Surveillance,