Humoral Response Assessment for SARS-CoV-2 and Variants

Evaluation of humoral response to spike protein, RBD, and nucleocapsid is critical in
SARS-CoV-2 vaccine and therapy research. Assess IgG and IgA response and viral neutralization quickly and accurately with assays used by many of the top SARS-CoV-2 vaccine developers.


  • Assess IgG responses in animal models (mouse, ferret, hamster, NHP) or humans
  • Optimized for development, qualified and validated for clinical studies
  • Automated liquid handlers
  • WHO/NIBSC calibration
  • IgA assays forthcoming
  • MSD 4-spot

Viral Neutralization Assays (VNA) / Pseudo Neutralization Assay (PNA)

We have established a PRNT assay using a wild-type SARS-CoV-2 strain. Running routinely at Public Health England BSL-3, it is being used to evaluate several drug and vaccine candidates.

We have also developed a pseudo-particle neutralization assay (PNA) using VSVΔG spike. This assay is calibrated to the WHO/NIBSC reference standard and has been evaluated as part of the SARS-CoV-2 Neutralization Assay Concordance Survey (SNACS). The pseudo-particles associated with the SARS-CoV-2 virus and its variants are generated at a Nexelis facility.

Cellular Response Assessment

Nexelis offers sophisticated methods of assessing cellular response via flow cytometry and ELISpot, including functionality after ex vivo restimulation and cell-mediated immune response for vaccine efficacy. Panels and markers can be customized as needed.

Molecular Biology, Biomarkers, and Bioanalysis

Nexelis has many resources for molecular biology and bioanalysis as well as a wide range of biomarker options that are constantly updated as knowledge evolves.

For viral shedding and epidemiology studies, we offer viral detection via RT-qPCR.