Table 1.
Broadly reactive antigens of influenza A viruses (IAVs), their conserved sites, cross-reactivity with other IAVs and reported immune stimulations.
| Antigen | Region | Conserved sites | Cross-reactivity with other IAVs | Immune stimulations | References |
|---|---|---|---|---|---|
| Hemagglutinin (HA) | Head domain | Residues 87–120 of E site from A/Catalonia/63/2009 or A/South Carolina/1/18 H1N1 strain | H1N1, H3N2, H5N1 | B cell and CD4 T cell | López-Serrano et al. (2021); Vergara-Alert et al. (2012) |
| Receptor-binding sites (positions 134–140, 156–162, 187–191, 224–230) of A/Solomon Islands/03/2006 H1N1 strain | H1N1 (different strain) | B cell | Caradonna et al. (2022) | ||
| Receptor-binding sites (residues Y98, G134, S136, W153, E190, L194) of H1, H2 and H3 IAVs | H1N1, H2N2, H3N2, H9N2, H12N5 | B cell | Ekiert et al. (2012) | ||
| Receptor-binding sites (residues G134, S136, W153, L194) of H3 IAVs | H1N1, H2N2, H3N2, H3N8, H13N6 | B cell | Lee et al. (2014) | ||
| 90-loop and 220-loop of A/Solomon Islands/3/2006 H1N1 strain or A/Hong Kong/3/1968 H3N2 strain | H1N1, H2N2, H3N2, H4N6, H5N1, H6N1, H7N7, H8N4, H9N2, H10N7, H11N9, H12N5, H14N5, H15N9 | B cell | Bangaru et al. (2019) | ||
| 220-loop and residues 99–105 of H3 and H1 IAVs | H1N1, H2N2, H3N2, H4N6, H5N1, H6N1, H7N9, H8N4, H9N2, H10N8, H14N6 | B cell | McCarthy et al. (2021) | ||
| Stem domain | Residues 344–357 of HA from A/New Caledonia/20/1999 H1N1 strain (NCBI accession no: AAP34324) | H1N1, H2N8, H3N3, H4N6, H5N1, H6N1, H7N2, H8N4, H9N2, H10N4, H11N1, H12N5, H13N5 | B cell | Chun et al. (2008) | |
| HA from A/California/07/2009 H1N1 strain | H1N1 (different strain), H5N1 | B cell, CD4 T cell and CD8 T cell | Bliss et al. (2022) | ||
| Stem of A/New Caledonia/20/1999 H1N1 strain and A/Jiangxi-Donghu/346/2013 H10N8 strain | H1N1, H3N2, H5N1, H7N9, H10N8 | B cell | Yassine et al. (2015); Moin et al. (2022) | ||
| Neuraminidase (NA) | N1 head region (computationally optimized) | Different strains of H1N1 and H5N1 | B cell | Skarlupka et al. (2021) | |
| Matrix 2 (M2) | Ectodomain of M2 from A/Puerto Rico/8/1934 H1N1 strain | H6N6, H9N2, H10N8 | B cell, CD4 T cell | Yao et al. (2019) | |
| Ectodomain of M2 from human, swine and avian IAVs | H3N2, H5N1 | B cell, CD4 T cell and CD8 T cell | Lee et al. (2018) | ||
| Nucleoprotein (NP) | Residues 147–155 of NP from H3N2 | H1N1 | CD8 T cell | McGee and Huang (2022) | |
| NP from A/Wilson-Smith/1933 H1N1 strain | H1N1 (different strain), H3N2 | B cell, CD4 T cell and CD8 T cell | Del Campo et al. (2019) | ||