ISSN: 2578-5044
Authors: Arcidiaco S, Schreiber P, Fournel S, Cronier J, Fontaine C, Poincelot L*, Ravida E, Loukeri S, Lesbros C, Gueguen S
Feline Leukaemia Virus (FeLV) is a viral pathogen causing fatal disease in cat populations worldwide, mainly in young kittens with outdoor access. This study aimed to assess the protection against feline leukaemia virus (FeLV), provided by a FeLV vaccine containing purified p45 FeLV-envelope antigen (Leucogen®) after one single injection of primary vaccination in kittens. Twenty-five 9-week-old cats, negative for FeLV antibodies and antigens the day of vaccination, were randomized into two groups. One group of 10 kittens was not vaccinated and kept as control, and one group of 15 animals received one dose of Leucogen® vaccine. The serological response was measured 14 and 21 days post vaccination. Three weeks after the vaccination, all kittens were inoculated by oronasal route with a virulent FeLV-A strain. The development of persistent viraemia was monitored for 15 weeks following inoculation. The animals were clinically monitored closely during the experimental phase. All cats remained in good health, presented physiological growth along the study and did not show any unexpected reaction after vaccination. In the control group, 90% of cats (9/10 cats) developed a persistent infection, confirming that this experimental infection model was valid, since the minimum of 80% required by the European monograph was achieved. On the other side, 73% of the vaccinated cats (11/15 cats) did not develop a persistent infection following the challenge strain inoculation. In the FeLV vaccinated group, 73% of cats were protected from the first vaccine injection. The first injection of primary vaccination with Leucogen® vaccine provided complete protection against FeLV persistent viraemia in 73% of the kittens. The second injection of the primary vaccination is necessary to ensure a complete protection of the whole population and a long lasting immunity. The early protection against FeLV infection conferred after one single injection of primary vaccination with FeLV vaccine containing purified p45 FeLV-envelope antigen could be a contributing factor in the reduction of prevalence of FeLV infection.
Keywords: Feline Leukaemia Virus, FeLV, Feline, Fat, Vaccine, Efficacy, Leucogen
