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In the present study, after vaccination and challenge with Newcastle disease virus, changes in the population of blood monocytes and lymphocytes of broiler chickens were evaluated using flow cytometry. 300 apparently healthy 1-day-old Cobb broiler chicks were divided randomly into four experimental groups (n = 75). At 20 days of age the chicks in group 1 and 2 were vaccinated with live B1 ND vaccine. Those in group 2 were additionally injected with a killed vaccine simultaneously and group 3 chicks received only the adjuvant of the killed vaccine. The birds in groups 1, 2 and 3 were challenged with a velogenic ND virus and those in group 4 were treated as control. Sampling was done on days 1,2,3,7 after vaccination and also on 1, 2, 3,7,14, 21 post challenge days. In this study percentage of B cell population was increased after vaccination and challenge in vaccinated birds, but CD3+ cells were decreased after vaccination and challenge, which showed B cells have more expansion than T cells. The CD4+ cell percentage in vaccinated birds was always lower than control birds. However, the percentage of CD8+ cells in vaccinated birds was increased. Results indicate increased CMI with the live NDV vaccination. In this study CD4/CD8 ratio in control birds was about 1.5 at 30 days of age and it was slightly lower in vaccinated and challenged birds. The percentage of monocytes in vaccinated birds was significantly higher than control birds from 3 days post vaccination to the end of the experiment. [ABSTRACT FROM AUTHOR]

Background Field vaccination trials with Mycobacterium bovis BCG, an attenuated mutant of M. bovis, are ongoing in Spain, where the Eurasian wild boar (Sus scrofa) is regarded as the main driver of animal tuberculosis (TB). The oral baiting strategy consists in deploying vaccine baits twice each summer, in order to gain access to a high proportion of wild boar piglets. The aim of this study was to assess the response of wild boar to re-vaccination with BCG and to subsequent challenge with an M. bovis field strain. Results BCG re-vaccinated wild boar showed reductions of 75.8% in lesion score and 66.9% in culture score, as compared to unvaccinated controls. Only one of nine vaccinated wild boar had a culture-confirmed lung infection, as compared to seven of eight controls. Serum antibody levels were highly variable and did not differ significantly between BCG revaccinated wild boar and controls. Gamma IFN levels differed significantly between BCG revaccinated wild boar and controls. The mRNA levels for IL-1b, C3 and MUT were significantly higher in vaccinated wild boar when compared to controls after vaccination and decreased after mycobacterial challenge. Conclusions Oral re-vaccination of wild boar with BCG yields a strong protective response against challenge with a field strain. Moreover, re-vaccination of wild boar with BCG is not counterproductive. These findings are relevant given that re-vaccination is likely to happen under real (field) conditions. [ABSTRACT FROM AUTHOR]