<p>Currently, control programmes for bovine tuberculosis (bTB) contemplate the use of vaccines to reduce disease incidence rates. The BCG vaccine and the culture filtrate protein extract (CFPE) of <i>Mycobacterium bovis</i> are strong candidates for vaccination against bTB. We conducted an analysis of the immune response and evaluated activation and memory markers in CD4⁺ and CD8⁺ T-lymphocyte subpopulations in Holstein–Friesian calves immunised with different doses of <i>M. bovis</i> BCG-Phipps vaccine (1×10⁴ and 1×10⁶ CFU) or with CFPE (300 µg and 600 µg) in a natural transmission setting. The study was carried out in a dairy herd, selecting calves aged 1–4 months that tested negative in various bTB diagnostic tests. In the groups immunised with the BCG-Phipps vaccine, gamma interferon (IFN-γ) secretion levels increased significantly, with the highest increase observed in the group that received a dose of 1×10⁶ CFU (<i>P</i> ≤ 0.05). The CD4⁺/CD8⁺ ratio increased significantly over time in both vaccinated and unvaccinated groups, with no significant differences between them. However, notable differences were observed in activated (CD25⁺) and memory (CD45RO⁺) CD4 and CD8 T-cell populations across different times and treatments. Remarkably, the groups immunised with the BCG vaccine remained free of <i>M. bovis</i> infection, as evidenced by negative IFN-γ results using ESAT-6/CFP-10 antigens and negative PCR test results for bacterial detection. The comparative analysis of the immune response induced by the different doses of the BCG-Phipps and CFPE vaccines revealed that the group of animals vaccinated with the 1×10⁶ CFU dose exhibited greater production of gamma interferon and a higher percentage of CD4⁺ T cells, as well as activated and memory CD8⁺ T cells compared to the other vaccinated and control groups in the natural transmission environment.</p>