In Ukraine the outbreak of African swine fever has been reported at first in 2012 (Zaporozhye region). In 2014 two types of outbreaks were recorded. One outbreak, which took place among wild boar was recorded in the Luhansk Region and five outbreaks took place in the Chernihiv Region. In the Chernihiv Region the two outbreak was recorded among the wild boar. It may be suggested that the causative agent was in the population of wild boars, although monitoring studies of previous years have shown no animal carriers. Therefore, the epizootic situation of the disease will only get complicated. Relatively positive in this situation, in comparison to the European countries, is negligible population of the wild boar in our country and insignificant as to such territory, the number of domestic pigs.

Thus, from the beginning of the year 24 outbreaks of the African swine fever were recorded in Lithuania, 7 in Estonia, 206 Latvia and 37 in Poland. However, in Europe the contact of domestic swine with materials or with transfer factors, which might contain a virus of the African swine fever, is eliminated. European pig farms operate as a closed-end company and therefore such contacts are completely eliminated. In Ukraine the livestock of 8 million pigs, 4.5 million of which are held in individual households (56%), where even the minimal biosecurity is not provided. In Belarus an individual sector is about 25% of domestic pigs and in Russia 36.7%. Many researchers have noted that wild boars are quite sensitive to the virus of the African swine fever, but nevertheless it is lower than the sensitivity of domestic pigs. Thus, according to Russian researchers in Sochi’s reserve approximately 85% of the wild boar in 2010 was killed, only around 15% of these animals have survived. However, it is easy to calculate that the population will recover in a few years, and in most cases the animals will stay the carriers of the virus (persistence of formation of latent forms of infection).

The short description of the immunity. Passive and maternal immunity is weak. The antibodies do not neutralize the virus. The reasons of the weak intensity of immunity and unneutralized activity are associated with features of the antigenic structure of the virus (blocking antigen with lipids, competition or masking of protective antigens species antigens of the virus or the host, as well as changes in the function of lymphoid cells - a violation of virus and antigen interaction with macrophages and cooperation of them with T- and B-lymphocytes (mechanisms of viral persistence).

In favor of the first hypothesis says weak or altered response to inactivated virus preparations in both sensitive and insensitive animals. In low activity of antibodies the cellular immune responses are enhanced. They are essential in blocking infection and are the cause of allergic and autoimmune complications.

In the pathogenesis and immune of the African swine fever autoallergic reactions play a significant role. In the event of attenuated strains of the virus on lymphoid cells is the synthesis of defective antibodies, which are unable to neutralize the virus. Antigen-antibody complexes, which are concentrated in the tissues of target organs, result in a violation of their functions and the development of allergic and autoallergic processes. The stimulation of cellular immunity - lysis of infected cells sensitized lymphocytes can be observed, along with the selection of mediators of cellular immunity: lymphotoxin, migration inhibition factor blasttrans-formation and so on.

Vaccines with attenuated strains have protected 80-100% of vaccinated animals (immunized animals in Spain and Portugal), but induced an elongated carrier (persistence) of the vaccine virus, caused vaccination complications and have not warned the acclimatization of the virulent virus. The quantity of immunological types of pathogen (22 genotypes) and the existence of mixed virus populations significantly limits the use of such drugs.

Inactivated vaccines do not eliminate problems of the typical plyuralities, carriers and engraftment virulent virus. This virus also established phenomenon of "antigenic mimicry".

In cells infected with the African swine fever found 106 virus specific proteins (for example, the causative agent of classical swine fever has only 8 virus specific proteins), 35 of which are synthesized before the start of viral DNA replication (early proteins) and 71 after DNA replication (late proteins).

Hence the development of vaccines using modern technology looks almost impossible. Thus, the development of vaccines at the present stage of the study of this disease today seems to be not realistic. On the forefront go at first the tough measures of fighting and control this dangerous disease.

Fighting the African swine fever in Ukraine is based on the destruction of potential sources of pathogen and strict veterinary and sanitary measures. In epizootic focus all susceptible animals (pigs of all ages) should be destroyed. The fighting measures should be at first preceded in the first zone of high risk of infection (the area that directly borders on epizootic extension on distance 3-20 km). This means slaughter pigs, which kept in holdings of all forms of ownership of processing enterprises, established by the State Department of veterinary medicine exclusively for the manufacture of cooked products. Secondly the measures for the destruction of wild pigs, wild animals, migratory birds and rodents should be organized. The measures against the African swine fever in the second threatening zone (the area surrounding the border of the first zone to a depth of 150 km from epizootic extension) includes immunization records and all livestock pig farms of all types of ownership against classical swine fever, followed by enhanced supervision over them.

African swine fever today is not only cross-border disease, but it is a global problem for the veterinary service in all countries. This is a new challenge for the economies of the countries with developed hog industry. Today this disease has already penetrated into the territory of the European Union, namely, Lithuania, Latvia, Estonia and Poland. It remains unclear how the pathogen came to Europe. It might be that the path of pathogen came through Belarus, where only 2 officially outbreaks were reported, although according to the mass media the magnitude of the outbreaks was much higher. Today in Ukraine 7 outbreaks of this dangerous disease were already recorded. Therefore, our country requires cooperation with EU and international cooperation in this field.

Key words: afriсan swine fever, transboundary іnfection, epіzootic situation, persisttncia, late onset іnfection, wild boar, the vaccine.