Table 2.
Efficacy of experiment FIV vaccines derived by molecular technologya
| Studyb | Vaccine(Route)cd | Challenge FIV CID50/Route)cd | Protection Rate | Comments (Reference) |
|---|---|---|---|---|
| Subunit Vaccine | ||||
| 1A | pDNA-Pet-env (ID/IM) | Pet | 1 / 4 | Enhanced plasma virus load in Group 1B (Richardson et al., 2002) |
| 1B | pDNA-Pet-env (IN) | (10/ IP) | 0 / 4 | |
| 1C | pDNA empty (ID/IM) | 1 / 8 | ||
| 2A | VRP-NCSU1-gag/env (SC) | NCSU1 | 0 / 4 | (Burkhard et al., 2002) |
| 2B | VRP-GFP (SC) | (cell / Vag) | 0 / 4 | |
| 3A | 19k1-Env protein (SC) | AM19 | 0 / 3 | Enhanced plasma virus load in vaccinates; 19k1 is molecular clone of AM19 (Huisman et al., 2004) |
| 3B | 19k1-Env(ΔV3–V5) protein (SC) | (20 / IM) | 0 / 4 | |
| 3C | PBS (SC) | 0 / 5 | ||
| 4A | LM-NCSU1-gag/pDNA-env (PO) | NCSU1 | 0 / 5 | Lower proviral load & higher CD4+ T cells (Stevens et al., 2004) |
| 4B | LM wt (PO) | (CF+cell /Vag) | 0 / 5 | |
| 4C | PBS (PO) | 0 / 5 | ||
| 5A | Pet-Orf-A protein (SC) | Plasma Pet | 0 / 5 | Early enhanced plasma virus load; later virus decrease & higher CD4+ T cells (Pistello et al., 2006) |
| 5B | pDNA-Pet-Orf-A (IM) | (10 / IV) | 0 / 5 | |
| 5C | pDNA-Orf-A (IM) + Orf-A protein (SC) | 0 / 5 | ||
| 5D | Alum (SC) or pDNA-empty (IM) | 0 / 8 | ||
| Attenuated Vaccine based on Deletion or Substitution | ||||
| 6A | GL8ΔIN+pDNA-IL18 (IM) | Pet | 1 / 6 | 4 protected cats became infected after GL8 challenge but has lower GL8 provirus & plasma virus loads than 4 controls (Dunham et al. 2002) |
| 6B | GL8ΔIN+pDNA-IL18+IL12(IM) | (25 / IP) | 2 / 6 | |
| 6C | GL8ΔRT+pDNA-IL18 (IM) | 2 / 6 | ||
| 6D | GL8ΔRT+pDNA-IL18+IL12 (IM) | 0 / 6 | ||
| 6E | pDNA + pDNA-IL18+IL12 (IM) | 0 / 6 | ||
| 7A | Pet-Δorf-A (SC) | Plasma Pet | 3 / 9 | (Pistello et al., 2005) |
| 7B | None | (10 / IV) | 0 / 6 | |
| 8A | Pet-env-TN14 (IP) | Wo | 0 / 5 | Pet and Wo from subtype A (Broche-Pierre et al., 2005) |
| 8B | Pet-env-TN92 (IP) | (10 / IP) | 1 / 5 | |
| 8C | Pet wt (IP) | 0 / 5 | ||
| 8D | None | 0 / 5 | ||
| 9A | GL8ΔIN+pDNA-IFNγ(IM), Pet-IWV (SC) | GL8 clone | 1 / 6 | Lower proviral PBMC & lymph node loads & higher CD4+ T cells in groups 9B & 9C; (Dunham et al., 2006) |
| 9B | GL8ΔIN+pDNA-IFNγ(IM) | (10 / IP) | 1 / 6 | |
| 9C | Pet-IWV (SC) | 0 / 6 | ||
| 9D | GL8ΔIN+pDNA-IFNγ(IM)+Pet-IWV (SC) | 0 / 6 | ||
| 9E | PBS (SC) | 0 / 6 | ||
| 10A | pDNA-PPRΔvifATG/IFNγ(IM) | PPR | 0 / 5 | (Gupta et al., 2006) |
| 10B | pDNA-PPRΔvif (IM) | (10 / IM) | 0 / 5 | |
| 10C | pDNA-PPRΔvif+pDNA-IFNγ (IM) | 0 / 5 | ||
| 10D | Saline (IM) | 0 / 5 | ||
Experimental vaccine trials reported in years 2002–2006 are shown for FIV vaccines derived by molecular technology. Earlier vaccine trials are summarized in previous publications (Elyar et al., 1997; Uhl et al., 2002).
FIV strains for vaccine and challenge are Petaluma (Pet), North Carolina State University-1 (NCSU1), Amsterdam-19k1 clone (19k1), Amsterdam-19 (AM19), Glasgow-8 (GL8), San Diego PPR (PPR), and France-Wo (Wo).
Subunit and attenuated vaccines are described with construct derivation, FIV strain of the vaccine, and FIV gene or protein of the vaccine. Vaccines consisted of plasmid DNA (pDNA), Venezuelan equine encephalitis virus-replicon particles (VRP), Listeria monocytogenes vector (LM), recombinant protein, inactivated whole virus (IWV), and deletion or substitution mutants. Adjuvants for protein vaccines were ISCOM (Study 3), alum (Study 5), and Quil A (Study 9). Attenuated vaccines consisted of substitution(s) in env gene (TN14, TN92) or deletions of integrase (ΔIN), reverse transcriptase (ΔRT), open-reading frame-A (Δorf-A), or vif (Δvif) gene. Controls were either non-immunized cats or cats immunized with wild type (wt) organism, saline, or PBS. Group 9A in Study 9 was primed IM with GL8ΔIN+pDNA-IFNγ and boosted SC with Pet-IWV.
Routes of immunization or challenge are intradermal (ID), intramuscular (IM), subcutaneous (SC), oral (PO), intraperitoneal (IP), vaginal (Vag), and intravenous (IV). The challenge inoculum for Study 4 was a combination of infected culture fluid and infected cells (CF+cell).