Compatibility between a rabies vaccine and a combined vaccine against canine distemper, adenovirosis, parvovirosis, parainfluenza virus and leptospirosis.

In many cicumstances, veterinarians are requiring to be able to administer rabies vaccine in dogs at the same time as vaccinating against canine distemper, adenovirus, parvovirus, parainfluenza virus and leptospirosis. The aim of this study was to assess the compatibility between a multivalent vaccine and a rabies vaccine when injected at two separate sites. Lack of interference was assessed by comparing serological response to viral components during one year following primary vaccination with vaccines administered alone or concomitantly. Antibody response to all tested components was comparable, irrespective of whether vaccines were administered individually or concurrently. Notably, the rabies vaccine induced very strong and protective seroconversion in dogs, whether it was administered concomitantly with the combo vaccine or not. This facilitates administration of rabies vaccine, which is a key factor for controlling the disease.

Use of DNA and recombinant canarypox viral (ALVAC) vectors for equine herpes virus vaccination.

In this study, experimental canarypox virus (ALVAC) and plasmid DNA recombinant vaccines expressing the gB, gC and gD glycoproteins of EHV-1 were assessed for their ability to protect conventional ponies against a respiratory challenge with EHV-1. In addition, potential means of enhancing serological responses in horses to ALVAC and DNA vaccination were explored. These included co-administration of the antigen with conventional adjuvants, complexation with DMRIE-DOPE and co-expression of the antigen along with equine GM-CSF. Groups of EHV primed ponies were vaccinated twice intra-muscularly with one dose of the appropriate test vaccine at an interval of 5 weeks. Two to 3 weeks after the second vaccination, ponies were infected intra-nasally with the virulent Ab4 strain of EHV-1 after which they were observed clinically and sampled for virological investigations. The results demonstrated that DNA and ALVAC vaccination markedly reduced virus excretion after challenge in terms of duration and magnitude, but failed to protect against cell-associated viremia. Noteworthy was the almost complete absence of virus excretion in the group of ponies vaccinated with ALVAC-EHV in the presence of Carbopol adjuvant or DNA plasmid formulated with aluminium phosphate. The administration of the DNA vaccine in the presence of GM-CSF and formulated in DMRIE-DOPE and of the ALVAC vaccine in the presence of Carbopol adjuvant significantly improved virus neutralising antibody responses to EHV-1. These findings indicate that DNA and ALVAC vaccination is a promising approach for the immunological control of EHV-1 infection, but that more research is needed to identify the immunodominant protective antigens of EHV-1 and their interaction with the equine immune system.