Mucosal assays for coronavirus vaccine R&D | |||
| Sample type | Assays | Notes | References |
| Nasal swab / wash / nasosorption | ELISA for anti-S/anti-RBD IgA/IgG; secretory IgA; pseudovirus/live-virus neutralization | Paired with serum/saliva to quantify mucosal Ig and function in the upper airway Nasosorption or swab eluates frequently used | |
| Saliva | ELISA for anti-S/anti-RBD IgA/IgG; neutralization | Accessible mucosal proxy; early, strong sIgA often detected (often correlates with faster viral clearance) | |
| Bronchoalveolar lavage (BAL) | Flow cytometry/ICS of SARS-CoV-2-specific T cells; ELISA/neutralization on BALF | Direct lower-airway immune profiling Enriched virus-specific T cells and antibodies relative to blood | |
| Tear / conjunctival fluid | ELISA for anti-SARS-CoV-2 IgA/IgG; multiplex cytokines | Non-invasive ocular mucosal sampling via Schirmer strips Local sIgA often detectable | |
| Stool | ELISA for antiviral IgA/IgG; cytokines; viral RNA by RT-qPCR | GI mucosal humoral readouts Stool sIgA reported in acute disease and after maternal vaccination | |
| Milk | ELISA for anti-S/anti-RBD IgA/IgG; neutralization | Post-infection or vaccination milk contains SARS-CoV-2-specific Abs | Stafford 2023 |
| Oropharyngeal / nasopharyngeal swab eluate/ nasal turbinates | ELISA for local Ig; sometimes neutralization | Used to detect local antibodies (especially post-exposure) even when serum is negative | |
| Lung tissue / airway-draining LNs | Flow cytometry (tissue-resident memory T/B cells), ELISpot; immunohistology | Demonstrates local TRM and antibody-secreting cells after mucosal vaccination/challenge; often correlated with sterilizing protection | |
Systemic assays for coronavirus vaccine R&D | |||
| Sample type | Assays | Notes | References |
| Serum / Plasma | Spike (S) ELISA; RBD ELISA; Nucleocapsid (N) ELISA | Quantitative binding ELISAs | |
| Serum | Microneutralization assay (MNA; live virus) | Live-virus neutralization assays | |
| Serum | Pseudovirus neutralization assay (PNA; VSV backbone) | Pseudotyped-virus neutralization assay Good correlation with MNA and with S-ELISA across clinical samples | |
| Peripheral Blood Mononuclear Cells (PBMCs) | IFN-γ / IL-5 ELISpot | Qualified T-cell ELISpot assay Proficiency testing uses blinded PBMC panels Usually applied as secondary/exploratory endpoints | |