Experience in controlling classical swine fever using booster vaccination

Abstract

The article presents experimental scientific data of epidemiological investigation of classical swine fever (CSF) among domestic pigs in the private sector and the use of booster doses of CSF vaccines on piglets. The aim of the study was to conduct an epidemiological study of the incidence of CSF among domestic pigs in the private sector. To confirm the efficacy of booster (tenfold) doses of ASV and LK-M vaccines against classical swine fever using clinical, pathological, anatomical and laboratory methods for diagnosing CSF disease and evaluating the effectiveness of CSF disease in piglets.
The experiments were conducted in the CSF chamber in the village of Khotiv, Kyiv-Svyatoshynskyi district of Kyiv, where 20 heads of unvaccinated piglets under two months of age weighing 10-12 kg, 1 piglet aged 7-8 months, 1 boar and 1 sow aged 1.5 years were kept. For the diagnostic purpose of the case of classical swine fever, in accordance with generally accepted methods, the hematological method with counting the number of blood leukocytes and the immunoperoxidase test for detection of antigens and antibodies to the swine fever virus were used. Piglets were vaccinated with dry lapinized ASV viral vaccine, and animals of the second group were vaccinated with LK-M viral vaccine.
Based on the results of the studies, it can be argued that in the outbreak of classical swine fever, the LK-M viral vaccine was more effective, which, unlike ASV, is able to stop the infectious process. In our opinion, this phenomenon is due to the fact that the live attenuated virus of the vaccine against classical swine fever in the amount of 100,000 ImD50 (tenfold dose of vaccination with the LK-M vaccine) probably exceeded the amount of field virus in the piglet's body and contributes to a more pronounced reaction of the immune system (formation of specific antibodies) and further neutralization of field virus and recovery of animals, whereas in the vaccine against classical swine fever the amount of live attenuated virus, even in a tenfold dose, was insufficient to stop the development of classical swine fever infection.
The analysis of the epizootic investigation of the case of classical swine fever in the private sector showed that the pathogen was introduced with food waste brought from canteens that had not been heat treated before feeding.
In the outbreak of classical swine fever, the LK-M virus vaccine proved to be more effective in stopping the infectious process due to the presence of a large amount of live attenuated vaccine virus in a tenfold dose, which exceeded the amount of field virus in the piglet's body and contributed to a more pronounced immunological response from the piglet's body and further neutralization of field virus and their recovery compared to the ASV vaccine.
In our opinion, in certain cases (e.g., preservation of breeds or breeding pigs), one of the promising measures in the event of the occurrence and elimination of a CSF outbreak is the use of tenfold doses of LK-M vaccine with the permission of the State Veterinary Service of Ukraine.