Effect of combined application of Zylexis and a vaccine against FHV-1 and FCV on selected immune response parameters in cats

The aim of the study was to evaluate the immune response in cats after the administration of Zylexis (group A), a vaccine against FHV-1 and FCV infections (group B), and a combination of the vaccine and Zylexis (group D). The evaluated parameters included the total number of leukocytes and lymphocytes in peripheral blood, the number of CD4 and CD8 lymphocytes, the ratio of CD4 to CD8 (CD4/CD8) and the concentration of antiFCV and anti-FHV-1 antibodies in the serum of the subjects, as well as the bacteriolytic activity of lysozyme and the haptoglobin level. Significantly higher values of almost all these parameters were recorded in cats receiving a combination of the immunostimulator and the vaccine during the whole study period compared to cats receiving only the immunostimulator or only the vaccine. Additionally, the increase in immunological parameters in animals from this group was positively correlated with the concentration of anti-FHV-1 and anti-FCV antibodies. This may indicate a stimulated humoral as well as cellular response. Neither Zylexis nor the vaccine alone induced as strong an immune response as the combined administration of the vaccine with the immunostimulator. This indicates that it may be advisable to combine vaccines against FHV-1 and FCV with immunostimulators to increase immunity against FHV-1 and FCV. Further studies of the influence of combined administration of vaccines and different immunomodulating preparations on the parameters of specific and non-specific immune responses in cats are necessary.