Animal vaccines (biological products) are made of microorganisms (bacteria, virus, mycoplasma, chlamydia, leptospira, etc.), metabolites of microorganisms, protozoa, animal blood or tissues, etc., and are processed and prepared for prevention, treatment, and diagnosis. Immunological preparations for specific infectious diseases or other related diseases. For animal vaccines, the applied pathogenic microorganisms should have good immunogenicity, and the products made after reproduction and treatment should be used to inoculate animals and produce correspondingly good immunity. 1. Types of vaccines (1) Traditional vaccines Traditional vaccines refer to vaccines made with bacterial or viral culture fluids or toxic tissues in conventional, conventional methods. Traditional vaccines play an important role in preventing livestock and poultry infectious diseases. The vaccines we currently use are mainly traditional vaccines. Traditional vaccines include the following main types: 1 Inactivated vaccines: Also known as dead vaccines. They are treated with physical or chemical methods that contain bacteria or viruses. They lose their infectivity or toxicity while maintaining good immunogenicity. After vaccination, animals can produce active or passive immunity. Inactivated vaccines are divided into tissue-inactivated vaccines (such as a piglet crystal violet vaccine) and culture-activated vaccines (porcine erysipelas aluminum hydroxide vaccine, porcine parvovirus vaccine). The vaccine is non-toxic, safe, stable in vaccine performance and easy to preserve and transport. It is the direction of vaccine development. 2 attenuated vaccine: also known as live vaccine, is the natural virulent of microorganisms through physical, chemical treatment and continuous subculture of the organism, so that it lost the pathogenicity of the original host animal or only caused a slight subclinical reaction, but still preserved Good immunogenic strains are used to prepare vaccines (eg, attenuated swine erysipelas vaccines, attenuated swine vaccines, etc.). In addition, attenuated vaccines can also be prepared from naturally attenuated strains screened in nature. 3 Monovalent vaccines: Vaccines prepared by using the same microbial strain (virus) strain or a single serotype (toxic) strain of a microorganism are called monovalent vaccines. The monovalent seedlings have good immune protective efficacy against the diseases caused by the corresponding single serotype microorganism (such as porcine pulmonary epidemic disease aluminum hydroxide bacterin, produced by virulent strains of 6:B serotype porcine-derived pasteurella viridis, No immunoprotective effect against Pneumococcal disease caused by Pasteurella multocida type A). 4 Multivalent vaccine: Refers to a vaccine prepared from a proliferating culture of several serotype (toxic) strains of the same microorganism. Multivalent vaccines allow complete protection of immunized animals (eg polyvalent paratyphoid bacilli in pigs). 5 mixed vaccine: that is, multi-joint seedlings, refers to the use of different microbial proliferation culture, according to the characteristics of the disease, according to the principles and methods of immunology, made up. After immunization of animals, it can produce immune protection against the corresponding disease, and can achieve the purpose of preventing multiple diseases (such as swine fever, swine erysipelas, and triple vaccine of lung disease). 6 Homologous vaccines: refer to vaccines prepared using the same species, homotypes, or homologous microorganisms and applied to the same type of animal for immunoprophylaxis (eg, pig plague rabbit attenuated virus vaccine, swine epidemic diarrhea vaccine, can be used to prevent various species Porcine swine fever and porcine epidemic diarrhea). 7 Heterologous vaccine: refers to a vaccine prepared by using different strains of microorganisms (viruses). After inoculation, the vaccine can be made resistant to pathogens that are not contained in the vaccine (for example, rabbit fibrovirus vaccine can make it resistant to rabbit myxomas. Disease, or a vaccine prepared with the same type of microbiological inoculum, that can be used to make it resistant to allopathic pathogens (such as cows, goats, pigs, pigs, inoculated with Brucella venom vaccine, can make cattle In addition, sheep and sheep get immunity to brucellosis. (2) Genetic engineering vaccines The vaccines prepared using genetic engineering techniques include subunit vaccines, live vector vaccines, gene deletion vaccines, and nucleic acid vaccines. 1 Subunit vaccines: Microorganisms are treated by physical and chemical methods to remove their ineffective substances, extract their effective antigens (such as bacterial decidua, flagella, and viral capsid proteins, etc.) and prepare vaccines (such as the E. coli pilus vaccine). . 2 live vector vaccine: using animal virus attenuated or avirulent strains such as vaccinia virus, virus, adenovirus, etc. as a carrier, insert the foreign antigen gene to construct a recombinant live virus vector, and generate virus cells (such as rabies live vector vaccine). 3 Gene-deleted seedlings: genetic manipulations are used to remove or inactivate gene sequences of disease-causing substances in pathogenic cells or viruses to make them become avirulent strains or attenuated strains but remain immunogenic (such as pseudorabies virus) Gene deletion vaccine). 4 Nucleic acid vaccines: The use of an antigenic genetic material of a pathogenic microorganism, which is inoculated to animals via plasmid vector DNA, can be used to transcribe and translate synthetic antigenic substances in animal cells to stimulate animals to produce a protective immune response (currently in the experimental stage). (3) Anti-idiotypic vaccines According to the network theory of internal regulation of the immune system, vaccines prepared using the unique antigenic epitopes (clusters) in the first antibody molecule can cause liquid and cellular immune responses after immunization against pathogens. Infection. This vaccine is currently still in the laboratory stage. 2. Establishing immunization programs in accordance with local conditions to improve immunization is an important measure to prevent the epidemic of swine farms. It should be noted that the establishment of immunization programs must consider the prevalence of epidemics in the region, the status of maternal antibodies, piglets, The age of onset of the pigs, pigs, the onset of the disease, the immunization interval and other factors as well as the previous immune effects. To formulate a good immunization program, not only should it be scientifically rigorous, but also be consistent with the actual conditions of the local herd, but also consider the immunization program recommended by the vaccine manufacturer. According to a comprehensive analysis, a complete immunization program was drawn up. The following are the commonly used immunization procedures for medium and small-scale pig farms for reference. (1) 1 species of boar calves: Immunized once a year in spring and autumn. Two kinds of sows: Each spring or autumn, immunization with attenuated vaccines against swine plague rabbits, or immunization with sows 30 days before delivery. 3 Piglets: 20-day-old and 70-day-old pigs were vaccinated with attenuated vaccine against porcine plague once, but they were also immunized once with pig attenuated attenuated vaccine before the birth of colostrum, and 2 hours after inoculation. Breastfeeding and boosting once every 70 days. 4 Normal pig farms can be immunized with triple vaccines of swine fever, swine erysipelas, and porcine lung disease at 50 days of age. The immunization period can reach 8 months. Only one immunization is required for commercial pigs. (2) Swine erysipelas and pigs with 1 case of porcine pulmonary epidemic disease: In the spring and autumn, vaccination with swine erysipelas and pneumococcal vaccine was performed once. 2 For normal pig farms, 50 to 70 days old piglets may be immunized once with swine erysipelas, swine pneumoconiosis or swine fever, swine erysipelas, swine pneumococcal triple vaccine or swine erysipelas, and pig flu vaccine. Immunization period is 6 months. (3) Piglets from piglets with E. coli disease were vaccinated once with E. coli diarrhea bacterins (K88, K99, 987p) 40 to 42 days and 15 to 20 days before childbirth. Piglets are passively immunized by colostrum antibodies. ] (4) Japanese encephalitis B vaccine is used to immunize 100-day old males and females with Japanese encephalitis vaccine before mosquito-fly season (about April-May). (5) Porcine parvovirus infections Male and female sows are immunized once a year with the porcine parvovirus vaccine. (6) Pigs with more than 25 kg of foot-and-mouth disease should be immunized once every 6 months with O-type foot-and-mouth disease inactivated vaccine. (7) Porcine epidemic diarrhea and transmissible gastroenteritis are 15 to 30 days before sow giving birth. They are immunized once with swine epidemic diarrhea vaccine or porcine transmissible gastroenteritis vaccine. Porcine epidemic diarrhea may also be used. And vaccination with porcine transmissible gastroenteritis vaccine. For pigs of various ages after weaning, the above vaccines can also be immunized. (8) The use of vaccines such as Mycoplasma hyopneumoniae, piglets paratyphoid fever, swine streptococcus, piglet erythrasma, porcine atrophic rhinitis, and pseudorabies vaccine can be selected according to the specific conditions of different pig farms. 3. The correct use of the vaccine to ensure that the pigs produce the expected immune effect after vaccination, should be aware of the correct use of the vaccine when using the vaccine. Each kind of vaccine has its own specific immune procedures and immune efficacy. It is the result of long-term research. Manufacturers usually provide methods of use and precautions that should be strictly controlled. In order to ensure the immune effect of vaccination, the following issues should be noted. (1) All kinds of vaccines must be purchased by special personnel and kept by special personnel to ensure the quality of the vaccine. (2) During the transportation and storage of various types of vaccines, care should be taken not to heat them. Live vaccines must be stored at low temperature. Inactivated vaccines should be stored at 4°C to 8°C. (3) The use of vaccines is carried out in a planned manner according to immunization procedures. Vaccination must be performed by technicians and other personnel. (4) The bottleneck of the vaccine should be inspected before use. Observe whether the vaccine bottle is damaged, whether the seal is tight, whether the bottle seal is complete, whether it is within the validity period, whether the dosage record is clear, and whether the diluent is clear, and record the vaccine manufacturer, Lot number, etc. for filing purposes. (5) Before the vaccination, the health status of the herd should be checked. The sick pigs should be temporarily vaccinated. The vaccination equipment (such as syringes, needles, and tweezers) must be disinfected in advance. According to the farm situation, one pig can change one injection needle or change one injection needle. (6) Antisera cannot be used at the same time when vaccinating. (7) During the immunization process, care must be taken that the disinfectant does not come into contact with the vaccine. (8) Once the vaccine is used unsealed, it must be used up on the same day and cannot be used again every other day. (9) In the immunization process, the vaccine should not be exposed to sunlight and should be placed in a cool place. (10) Before immunizing piglets, special attention should be paid to preventing the effect of maternal antibodies on the immune effect. Therefore, immunization procedures must be strictly followed. 4. Causes and Countermeasures of Immunity Failure After the vaccination of pigs, the epidemic of the epidemic cannot be controlled at times. That is, immune failure occurs. The main causes of immune failure are the following aspects. (1) The immune function of the pig itself is abnormal. After the immunization, the pig cannot produce specific antibodies. (2) The interference of maternal antibodies, maternal antibodies can interfere with the antigenicity of the vaccine, so before using the vaccine, maternal antibody levels in the pig should be fully considered, and testing should be performed when necessary to avoid such interference. (3) There is no immunization according to the prescribed immunization procedure so that the required immune effect cannot be achieved after immunization. (4) Pigs are only sick and are being treated with antibiotics or immunosuppressive drugs, resulting in impaired antigens or immunosuppression. (5) The vaccine is improperly handled in the process of purchase, transportation, and preservation, which impairs the efficacy of the vaccine itself. (6) Vaccines are not well kept or operated during the immunization process, or the vaccine dose is insufficient. (7) The serotype of the strain used for the preparation of the vaccine is inconsistent with the serotype of the actual epidemic disease and does not achieve good protection. (8) During immunization, inappropriate immunization procedures or simultaneous use of antisera. In short, there are many reasons for immune failure. To conduct comprehensive inspections and analysis, it is of utmost importance to ensure proper use of vaccines and immunization in strict accordance with immunization procedures in order to prevent immunization failure.
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