Table 1.
Overview principles of serological and immunological tests
| Detection targets | Advantages | Limitations | When to apply | |
|---|---|---|---|---|
| Lateral flow immunoassay (LFIA) | IgM, IgA, IgG or total antibodies |
- Suitable as point-of-care test - Rapid and easy testing |
- Heterogeneous performance with overall limited sensitivity during acute phase of disease - Only qualitative results |
- Population-based epidemiological surveillance - For individual patient care in case of unavailability of molecular diagnostic tests, inconclusive molecular test results, late presentations during disease course or late-onset post-infectious complications - Implications for interpretation after vaccination and correlation with protective immunity remain to be determined |
| Enzyme-linked immunosorbent assay (ELISA) | - Overall higher sensitivity in comparison to LFIA - Suitable for high throughput and automation - Some assays generate quantitative results |
- Not suitable for rapid testing - Need for trained laboratory staff - Batchwise workup in laboratory process |
||
| Chemiluminescence immunoassay (CLIA) | ||||
| Plaque reduction neutralization tests (i.e. conventional virus neutralization test) | Total antibodies (that can inhibit viral replication) | - Presumably high correlation with protective immunity - Gold standard for quantification of neutralizing antibodies |
- Only in biosafety level 3 laboratories possible - Time consuming test |
- To increase scientific understanding regarding immunity - Implications for interpretation after vaccination and correlation with protective immunity remain to be determined |
| Pseudo-neutralizing antibody assays/surrogate virus neutralization test (sVNT) | - High correlation with plaque reduction neutralization tests - Rapid and safe (no need for live biological material) |
- Not considered as gold standard for quantification of neutralizing antibodies | ||
| ELISpot | Antigen-specific T cells (producing a specific cytokine, e.g. IFNγ) | - Quantitative measurements - Commonly used for evaluation of immunity in vaccination trials |
- No information regarding exact cytokine-producing cell types | - To increase scientific understanding regarding immunity - Implications for interpretation after vaccination and correlation with protective immunity remain to be determined |
| Flow cytometry | Different cell types, including T cells | - Identification of specific cell subpopulations and presence of polyfunctional cells | - Test is (relatively) complex | |