Table 2.
Comparative table of preclinical research studies with Adenoviral vector-based COVID-19 vaccine candidates.
| Vaccine | Species (animal number per group) | Viral particle per animal | Regimen | Route of administration | Humoral immune response | Cellular immune response | Neutralizing antibodies | Viral RNA detected after vaccination | Prevents COVID-19 disease | Reference |
|---|---|---|---|---|---|---|---|---|---|---|
| Ad5-nCOV | Mus musculus (10) | 5 × 107–9 | 4 weeks before challenge | Intramuscular | Yes | Yes | Yes | No with mucosal vaccination | Yes | [86] |
| Mustela putorious furo (6) | 5 × 1010 | 4 weeks before challenge | Intranasal | Yes | Yes | Yes | No with mucosal vaccination | Yes | ||
| hAd5 S-Fusion + N-ETSD | Mus musculus (5) | 1 × 1010 | Injections on Day 0, 21 and 28 | Subcutaneous | Yes | Yes with CD4+ and CD8+ T-cell responses | Yes | NA | Yes | [97] |
| VXA-COV2-1 | Mus musculus (6) |
1 × 107 1 × 108 |
Week 0 and Week 4 | Intranasal | Yes | Yes with CD4+ and CD8+ T-cell responses | Yes | NA | Yes | [100] |
| AdCOVID | Mus musculus (10) |
6 × 106 6 × 107 3.35 × 108 |
Single | Intranasal | Yes with mucosal IgA | Yes with CD4+ and CD8+ T-cell responses | Yes | NA | Yes | [104] |
| Ad26.COV2-S | Rhesus macaques (4–6) | 1 × 1011 | Single dose | Intramuscular | Yes | Yes with CD4+ and CD8+ T-cell responses | Yes | No (only 1 animal in nasal swab) | Yes | [108] |
| Gam-COVID-Vac/ Sputnik V | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| GRAd-COV2 | Cynomolgus macaques (4) | 5 × 1010 | Single-dose | Intramuscular | Yes | Yes with CD4+ and CD8+ T-cell responses | Yes | NA | NA | [120] |
| ChAdOX1-nCOV | Rhesus macaques (6) | 2.5 × 1010 | prime-only or a prime-boost regimen | Intramuscular | Only prime-boost regimen | Yes (did not increase after the second dose) | Yes | Only in nasal swab (not in the lungs) | Yes | [99] |
| ChAd-SARS-CoV-2 | Mus musculus (5–9) | 1 × 1010 | Subsets with boost immunization at week 4 | Intramuscular | Yes | Yes with CD4+ and CD8+ T-cell responses | Yes | Yes (low level in the lungs) | Yes | [138] |
| Intranasal | Yes with mucosal IgA | Yes with CD4+ and CD8+ T-cell responses | Yes | No | Yes | |||||
| Mesocricetus auratus (10) | 1 × 1010 | Single-dose | Intramuscular | Yes | NA | Yes | 10-fold less* | Yes | [139] | |
| Intranasal | Yes | NA | Yes, several-fold higher than IM | 100-fold less in nasal swab* | yes |
* Compared to ChAd-control immunized animals
NA not available, IgA immunoglobulin A, IM intramuscular, Adm. Administration, IM intramuscular, IN intranasal, SC subcutaneous, N nucleocapsid peptide, S spike, Th1 1 T helper cell, NAb neutralizing antibodies, IgG immunoglobulin G, IgA immunoglobulin A, BAL bronchoalveolar lavage.