Table 1.
Recent Clinical Studies That Evaluated Anti‐SARS‐COV‐2 Antibodies in COVID‐19
| Author | Publication Date | Study Design (n) | Test | Patient Population | Longitudinal Follow‐Up | Main Results | Limitation |
|---|---|---|---|---|---|---|---|
| Premkumar et al 19 | June 11, 2020 | Prospective cohort (n=63) | IgG/IgM binding to spoke RBD antigen and SARS‐CoV‐2 neutralization assay | Symptomatic PCR confirmed subjects with SARS‐CoV‐2 | 39 d | Strong correlation between levels of RBD‐binding antibodies and SARS‐CoV‐2 neutralizing antibodies |
Single center Small sample Short surveillance period |
| Steensels et al 11 | June 15, 2020 | Cross‐sectional (n=4125) | IgG/IgM Lateral flow assay against nucleocapsid protein* | Asymptomatic workers at Hospital East‐Limburg | 8 d | 6.4% had IgG antibodies to SARS‐CoV‐2 |
Single center No long‐term follow‐up Short‐surveillance period Only 74% of total sample enrolled |
| Long et al 2 | June 18, 2020 | Matched case‐control (n=178) | IgG and IgM ELISA against spike protein | Asymptomatic cases, defined as individuals with a positive nucleic acid test result with without clinical symptoms | 8 wk |
20.8% had asymptomatic infection (37/178) Median percentage decrease in IgG level was 71.1% (range, 32.8%–88%) Neutralizing antibodies decreased by 81.1% |
Inaccurate estimate of asymptomatic infection in general population Variability in sensitivity/specificity Confounding because of prior SARS infections |
| Wang et al 12 | July 7, 2020 | (n=23) | IgG and IgM ELISA to spike, S1, S2, RBD, and nucleocapsid proteins | Symptomatic cases (12 severely ill and 11 mildly ill) from 3 hospitals | 6 wk after symptom onset (baseline was measured during symptom onset) |
Lower level of IgM was observed in mildly ill patients, but similar IgG responses in mildly and severely ill patients Anti‐SARS‐CoV‐2 spike and nucleocapsid IgG levels correlated with neutralization titers |
Small sample Short follow‐up period |
| Wajnberg et al 13 | July 17, 2020 | Prospective cohort (n=51 829) | IgG ELISA against spike protein | Confirmed SARS‐CoV‐2 infection by PCR or suspected disease | 82 d (range of interval after symptom onset 52–104 d) |
38% had ELISA antibody test IgG spike protein at baseline |
Follow‐up beyond 3‐mo not available |
| Wu et al 20 | July 24, 2020 | Prospective cohort (n=349) | IgM and IgG ELISA RBD of the spike protein | Symptomatic patients with COVID‐19 | 26 wk |
IgG against spike and nucleocapsid was maintained at high positive rates and titers at 6 mo IgG positively correlated with neutralizing activity |
Missing samples at 9 and 11 wk Not all samples were assessed in virus neutralizing tests |
| Rodda et al 14 | August 15, 2020 | Prospective case‐control (n=15) | IgM, IgA, and IgG ELISA against RBD spike protein | Mildly symptomatic PCR‐confirmed COVID‐19 | 3 mo following symptoms onset (median=86 d) | Sustained immunity (including neutralizing antibodies) against SARS‐CoV‐2 | Small samples |
| Gudbjartsson et al 15 | September 1, 2020 | Prospective cohort (n=1797) | Pan‐immunoglobulin assays, antibodies against nucleocapsid, RBD, S1 | Symptomatic participants recovered from COVID‐19 | 3 mo after recovery |
Over 90% of qPCR‐positive patients tested positive with both pan‐Ig antibody and remained positive at 120 d after diagnosis Some diminution of antibody titer was observed |
Low prevalence of infection in Iceland |
| Patel et al 16 | September 4, 2020 | Prospective cohort (n=249) † | IgG ELISA against spike protein | Convenience sample of healthcare personnel at Vanderbilt University Medical Center | 60 d |
7.6% had anti‐SARS‐CoV‐2 antibodies at baseline 42% had antibodies that persisted at 60 d All participants who were positive at baseline had antibody titers decrease at 60 d |
Single center Small sample Convenience sampling Lacking information on timing of infection |
| Ibarrondo et al 17 | September 10, 2020 | Prospective cohort (n=34) | IgG ELISA against spike protein | Participants recovered from mild COVID‐19 infection | Mean 86 d (range, 44–119 d) | The estimated mean change in IgG level was an estimated half‐life of 36 d |
Short follow‐up of ≈3 mo Small sample size |
| Bolke et al 18 | September 23, 2020 | Prospective cohort (n=151) | IgA and IgG antibodies | Symptomatic participants | 120 d after the onset of symptoms | IgA and IgG levels remained unchanged |
Small sample Limited reported data |
| Terpos et al 18 | September 23, 2020 | Phase 2 prospective cohort (n=259) | IgG and IgA antibodies against spike protein S1 | Symptomatic participants or +PCR | 100 d | Rapid reduction in anti‐SARS‐CoV‐2 antibody in patients recovered from COVID‐19 | Limited data |
| Katsuna et al 18 | September 23, 2020 | Prospective cohort (n=81) | ELISA antibodies against spike protein | Symptomatic participants (mild, moderate, and severe disease) | 60 d |
Titers were higher in those with severe disease All patients showed decreased antibody titers after 60 d of symptom onset |
Limited data |
| Ripperger et al 21 | October 5, 2020 | Prospective cohort (serum samples 75) | ELISA antibodies against RBD and S2 | Symptomatic and asymptomatic PCR confirmed patients with COVID‐19 | 3 mo post disease onset |
Spike RBD and S2 and neutralizing antibodies remained detectable 5–7 mo post‐onset α‐nucleocapsid capsid titers diminished |
Seroconversion from (+) to (−) before testing No data beyond 226 d |
| Wajnberg et al 22 | October 28, 2020 | Prospective cohort (n=30 082) | IgG ELISA against spike protein | Mild‐to‐moderate confirmed SARS‐CoV‐2 infection by PCR or suspected disease or exposure to SARS‐COV‐2 | 5 mo | Anti‐spike binding titers significantly correlate with neutralization of authentic SARS‐CoV‐2 | No follow‐up date beyond 5 mo |
| Ladhani et al 23 | November 6, 2020 | Prospective cohort (n=518) | IgG ELISA against spike protein and nucleocapsid and neutralization assay | Asymptomatic and Symptomatic | Median=36 d | Most participants had neutralizing antibodies during follow‐up regardless of age and symptoms |
Survival bias Lack of serial testing to infected individuals |
| Dan et al 24 | November 16, 2020 |
Cross‐sectional (n=185) Prospective follow‐up (n=41) |
IgG ELISA against spike protein | Asymptomatic‐Mild‐moderate‐severe COVID‐19 cases | 6 mo | Spike IgG was relatively stable >6+ mo |
Many of original sample were lost to follow‐up Serial measurements with 3 time points are lacking |
| Dan et al 25 | January 6, 2020 | Prospective cohort (n=188) |
IgG ELISA against spike protein RBD IgG SARS‐CoV‐2 neutralizing antibodies |
Asymptomatic‐Mild‐moderate‐severe COVID‐19 cases | 6 mo | Spike IgG was relatively stable >6+ mo |
Serial measurements with 3 time points are lacking |
COVID‐19 indicates coronavirus disease 2019; IgA, immunoglobulin A; IgG, immunoglobulin G; IgM,immunoglobulin M; PCR, polymerase chain reaction; RBD, receptor binding domain; and SARS‐CoV‐2, severe acute respiratory syndrome coronavirus 2.
Immunoglobulin M results were excluded.
Six‐hundred healthcare personnel were eligible.