Table 2.
A summary of methods for the assessment of immunogenicity against infection and vaccination
| Notes | |
|---|---|
| Humoral response to structural proteins | |
| IgG/IgM against spike protein | ELISA: most commonly reported; correlate with infection severity; likely reflects subsequent response; unclear disease prevention and efficacy |
| IgG against receptor-binding domain | |
| IgG against membrane protein | |
| Neutralization assay | Most time-consuming |
| Pseudovirus | SARS-CoV-2 spiked lentivirus |
| Live virus | Readout usually reflects half maximal inhibitory concentration |
| Focus reduction neutralization assay | |
| Plaque reduction neutralization assay | |
| Cellular response | |
| ELISpot: either T or B cell | Activation of single cells by specific Ag (i.e., spike protein, membrane protein, or a panel of SARS-CoV-2–related peptides) |
| Requires PBMCs | |
| Cytokine response | IFN-γ, TNF, IL-2 |
| Ag-specific T cells | CD4/CD8+ cells |
| Memory B-cell responses | Flow cytometry using tetramer staining |
Ag, antigen; ELISA, enzyme-linked immunosorbent assay; IFN-γ, interferon-γ; IL-2, interleukin-2; PBMC, peripheral blood mononuclear cell; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; TNF, tumor necrosis factor.