Table 3

Examples of the role of diagnostics in assessing vaccine immune responses9

Test typeExamples
Antibody tests
  • ELISA-binding assay: to detect LASV-binding antibodies and cross-reaction between clades (clades I–IV).

  • ELISA-Competition: to define epitope specificity of binding antibodies to LASV GP.

  • Neutralisation assay-LASV GPC: to detect antiviral neutralising antibodies/breadth of response (clades I–IV).

T cell response tests
  • ELISPOT: to quantify LASV vaccine-induced specific T cell responses or to quantify vector-specific T cell responses.

  • Vectored antigen presentation assay.

Immune profiling
  • LASV-specific CD4 and CD8 T cells: to perform phenotypic and functional characterisation of T cells; to characterise vector-specific T cell response.

  • Transcriptomics: gene expression profile characterisation of early immune responses and to identify potential effector function correlates.

Antigen tests
  • ELISA assay: to detect LASV viral protein.

  • RDT: to detect LASV viral protein.

Nucleic acid tests
  • qRT-PCR: detection of vector RNA.

  • ELISPOT, enzyme-linked immunospot; GP, glycoprotein; GPC, glycoprotein precursor; LASV, Lassa virus; qRT-PCR, quantitative reverse transcriptase PCR; RDT, rapid diagnostic test.