A vaccination strategy consisting of Semliki-Forest-virus (SFV) DNA prime and fowlpox-virus boost significantly protects mice from a recombinant (HIV-1) vaccinia-virus infection

The use of DNA vectors based on the SFV (Semliki Forest virus) replicon have not been reported in the modality of DNA prime virus boost. In the present study, SFV DNA vectors (DNA vectors based on the SFV replicon) bearing the HIV-1 TAB9 multiepitopic polypepticle minigene were evaluated as priming DNA immunogens followed by a recombinant fowlpox expressing the TAB9 mutiepitope (FPTAB9LZ) boost. The results indicated that mice primed with pSFV(k)tab9 and boosted with FPTAB9LZ significantly decreased the HIV-1 recombinant (VVTAB13, a recombinant vaccinia virus expressing the TAB13 multiepitope) vaccinia virus replication, compared with groups given pSFV(k)tab9 vector and FPTAB9LZ virus alone. Additionally, the viral titre in ovary correlated with the number of specific gamma-interferon-secreting T-cells in spleen. These results support the possible use of SFV DNA vectors in prime-boost approaches implemented in therapeutic/prophylactic treatments for infectious diseases such as HIV-1.