Indagini sperimentali su un immunomodulatore

In one experiment 16 calves were divided in two groups of 8, then 4 calves in each group were injected with the immunomodulator Baypamun whereas the remaining 4 calves in each group were not treated with the immunomodulator and served as untreated controls. After 2h following the first injection of Baypamun, all calves of group 1 were given Bovine herpesvirus-1 (BHV-1) by nasal spray. The calves of group 2 were not inoculated with the virus but were housed together with the experimentally infected calves (group 1). All calves became infected but the calves treated with Baypamun and kept in contact with the experimentally infected calves did not show any signs of disease, whereas the untreated calves of group 2 underwent a clinical response typical of BHV-1 respiratory infection. The shedding of virus by calves treated with the immunomodulator was also significantly reduced. In the second experiment, 1 calf was infected with BHV-1 and mixed with other 5 calves of which, I had been vaccinated with a BHV-1 vaccine one month earlier. The other 4 calves were vaccinated at the time the experimentally infected calf developed the first signs of the disease, i.e on post infection day (PID) 2. Moreover, 2 of the latter 4 vaccinated calves also received simultaneously the immunomodulator. The calf that was vaccinated one month before the start of the experiment did not show any signs of disease. Of the remaining 4 calves, the 2 which received the vaccine only experienced a classic form of infectious bovine rhinotracheitis (IBR). In contrast, the 2 vaccinated calves which also received the immunodulator remained healthy during the entire observation period of 30 days. Finally, in a further trial six calves were given the immunomodulator Baypamun and housed together with other six calves of which, three were experimentally infected with BHV-1 and three served as untreated controls. The three experimentally infected calves as well as the three controls developed clinical signs of the typical acute form of BIR. Of the calves treated with Baypamun, those that had only one injection of the immunomodulator, either at the start of the experiment (time O) or 2 days later, underwent a much milder form of IBR and recovered in a shorter time than the experimentally infected calves or the controls. The calves that received four injections of the immunomodulator, i.e. at time O and subsequently of the next three days, remained healthy throughout the 30 days of observation. Moreover, the virus shedding by the Baypamun treated calves was significantly reduced.