Combined administration in a single injection of a feline multivalent modified live vaccine against FHV, FCV, and FPLV together with a recombinant FeLV vaccine is both safe and efficacious for all four major feline viral pathogens

Abstract

Nobivac Tricat, a lyophilised trivalent modified live attenuated vaccine is routinely used to protect cats against three commonly diagnosed feline viral pathogens namely herpesvirus, calicivirus and panleukopenia virus. The recognition of feline leukaemia virus (FeLV) as an important viral pathogen has prompted the development of an efficacious liquid recombinant subunit FeLV vaccine (p45 envelope protein). Lyophilised Tricat vaccine was dissolved in the liquid FeLV vaccine and no detectable deleterious effect on the titre of any of the live virus components was observed after 2h incubation. In vivo studies where the vaccines were mixed in the same syringe prior to inoculation showed no alteration to the safety profile assessed by repeat and overdose studies. Serological comparisons of the modified live viral antibody titres showed no evidence of reduced responses following administration of the mixed products. Challenge studies using pathogenic herpesvirus and FeLV revealed no difference in the degree of clinical protection. This paper shows that neither safety nor efficacy is adversely affected as a result of mixing the two vaccines.

Fig 1.

Schematic representation of the kinetics of mean antibody responses (log₁₀) to FHV, FCV and FPLV in MDA positive 8–9-week-old kittens following vaccination. As can be seen the magnitude of the antibody responses to all the vaccinal antigens in all three groups was similar at the end of the recommended primary vaccination scheme (experiment 2).

Fig 2.

Group mean antibody responses to FHV, FCV and FPLV in MDA negative kittens 3 weeks following the completion of their secondary vaccination scheme. Titres are expressed in log₁₀ and were similar between the different vaccinated groups for all the vaccinal antigens. The control groups remained seronegative throughout the course of this experiment (experiment 3).

Fig 3.

FHV isolation results (mean titres per group) after challenge with wild type FHV (experiment 3).