The infectious bronchitis virus (IBV) causes a highly contagious disease, spread worldwide, leading to serious economic losses. Sometimes the disease is associated with other entities such as infectious bursal disease virus, Newcastle disease virus, Mycoplasma gallisepticum and Escherichia coli. The highly genetic variability of the virus has generated a large number of viral strains with different clinical presentations. The objective was to assess the dynamics of the virus antibodies in birds vaccinated and not vaccinated against IBV, hosted on a broiler farm where the agent was detected by RT-PCR in Fusagasuga, Colombia and vaccinated birds in semi-isolation conditions in Bogota. To order this, 3 groups of birds (Ross 308) from 1 day of age (44 birds/group), which were vaccinated with a live attenuated virus strain Massachusetts H120, and the immune response was evaluated through the Elisa test. Since day 24 of age the birds showed a progressive decrease in antibody titers in all three groups, although in the vaccinated and unvaccinated birds kept at the farm were found higher levels of antibodies in the group of semi-isolation. Starting at day 28 in the birds housed in field, the antibodies titles rose slightly until the end of cycle. The slight increase in the level of antibodies may result from exposure to the virus vaccine generated a reversal of pathogenic viral persistence or a late exposure to field virus.