Coccidiosis is a ubiquitous intestinal protozoan infection of poultry seriously impairing the growth and feed utilization of infected animals. Conventional disease control strategies have relied on prophylactic medication. Due to the continual emergence of drug resistant parasites in the field and increasing incidence of broiler condemnations due to coccidia, novel approaches are urgently needed to reduce economic losses. Understanding the basic biology of host-parasite interactions and protective intestinal immune mechanisms, as well as characterization of host and parasite genes and proteins involved in eliciting protective host responses are crucial for the development of new control strategy. This review will highlight recent developments in coccidiosis research with special emphasis on the utilization of cutting edge techniques in molecular/cell biology, immunology, and functional genomics in coccidia vaccine development. The information will enhance our understanding of host-parasite biology, mucosal immunology, and host and parasite genomics in the development of a practical and effective control strategy against Eimeria and design of nutritional interventions to maximize growth under the stress caused by vaccination or infection. Furthermore, successful identification of quantitative economic traits associated with disease resistance to coccidiosis will provide poultry breeders with a novel selection strategy for development of genetically stable, coccidiosis-resistant chickens, thereby increasing the production efficiency.
Animals ; Biotechnology/methods ; Chickens ; Coccidiosis/prevention&control/*veterinary ; Eimeria/*immunology ; Poultry Diseases/parasitology/*prevention&control ; *Protozoan Vaccines

Despite the intensive vaccination policy that has been put in place to control Newcastle disease virus (NDV), the recent emergence of NDV genotype VII strains in Korea has led to significant economic losses in the poultry industry. We ssessed the ability of inactivated, oil-emulsion vaccines derived from La Sota or Ulster 2C NDV strains to protect chickens from challenge with Kr-005/00, which is a recently isolated Korean epizootic genotype VII strain. Six-week-old SPF chickens were vaccinated once and challenged three weeks later via the eye drop/intranasal route. All vaccinated birds were fully protected from disease, regardless of the vaccine strains used. All vaccinated and challenged groups showed significant sero-conversion 14 days after challenge. However, some vaccinated birds, despite being protected from disease, shed the challenge virus from their oro-pharynx and cloaca, albeit at significantly lower titers than the unvaccinated challenged control birds. The virological, serological, and epidemiological significance of our observations with regard to NDV disease eradication is discussed.
Administration, Intranasal ; Animals ; Chickens ; Cloaca/virology ; Disease Outbreaks/prevention & control/*veterinary ; Korea ; Newcastle Disease/*immunology/prevention & control ; Newcastle disease virus/*immunology ; Ophthalmic Solutions ; Poultry Diseases/*immunology/prevention & control ; *Vaccines, Inactivated/administration & dosage ; Viral Vaccines/*administration & dosage ; Virus Shedding/drug effects

The rapid mutation and widely spread of duck hepatitis A virus (DHAV) lead to the vast economic loss of the duck industry. To prepare and evaluate bivalent inactivated vaccine laboratory products of DHAV, 6 strains were screened from 201 DHAV-1 strains and 38 DHAV-3 strains by using serotype epidemiological analysis in most of the duck factory. Vaccine candidate strains were selected by ELD50 and LD50 tests in the 6 strains. Continuously passaged, the 5th passaged duck embryos bodies grinding fluid was selected as vaccine virus seeds. The virus seeds were treated with formaldehyde and water in oil in water (W/O/W) emulsions, making into three batches of two bivalent inactivated vaccine laboratory products. The safety test, antibody neutralization test, challenged protection and cross immune protection experiment suggested that the vaccines possessed good safety, and neutralizing antibodies were detected at 7th day and the challenged protection rate reached 90% to 100% at the 14th and 21st day. Moreover, immune duration of ducklings lasted more than five weeks. However, cross-immunity protection experiments with DHAV-SH and DHAV-FS only had 20%-30%. The two bivalent inactivated vaccine laboratory products of duck viral hepatitis were effective and reliable, providing a new method as well as a new product for DHAV prevention and control.
Animals ; Antibodies, Neutralizing ; blood ; Ducks ; virology ; Hepatitis Virus, Duck ; Hepatitis, Viral, Animal ; prevention & control ; virology ; Neutralization Tests ; Picornaviridae Infections ; prevention & control ; veterinary ; Poultry Diseases ; prevention & control ; virology ; Vaccines, Inactivated ; immunology ; Viral Hepatitis Vaccines ; immunology

Since 2002, H7 subtype avian influenza viruses (AIVs) have caused more than 100 human infection cases in the Netherlands, Italy, Canada, the United States, and the United Kingdom, with clinical illness ranging from conjunctivitis to mild upper respiratory illness to pneumonia. On March 31st, three fatal cases caused by infection of a novel reassortant H7N9 subtype were reported in Shanghai City and Anhui Province in China. With the ability of H7 subtype to cause severe human disease and the increasing isolation of subtype H7 AIVs, we highlighted the need for continuous surveillance in both humans and animals and characterization of these viruses for the development of vaccines and anti-viral drugs.
Animals ; Chickens ; Ducks ; Humans ; Influenza A virus ; genetics ; isolation & purification ; pathogenicity ; physiology ; Influenza Vaccines ; genetics ; immunology ; Influenza in Birds ; immunology ; prevention & control ; virology ; Influenza, Human ; immunology ; prevention & control ; virology ; Poultry Diseases ; immunology ; prevention & control ; virology ; Turkeys

Seeds of a Chinese traditional medicine plant, Cochinchina momordica were used in the present study for the improvement of influenza vaccine (H5N1) in chicken. Crude extraction from Cochinchina momordica seed (ECMS) was obtained by ethanol extraction method. In experiment No. 1, two weeks old chickens were immunized with influenza vaccine (H5N1) alone or combined with ECMS (5, 10, 20, 40 and 80 microg/dose). Serum IgG antibody levels (by ELISA) as well as effects on daily weight gain were measured on 0, 7, 14 and 28th day after immunization. Results revealed that all ECMS groups numerically increased the antibody levels while 10 and 20 microg/dose groups significantly (P<0.05) enhanced total IgG antibody on day 28, when compared with control. Average daily weight gain was also significantly higher in 20 microg/dose ECMS group. Adjuvant effect was also confirmed in experiment No. 2 when chickens were immunized with 20 microg/dose ECMS and antibody titer was measured through hemagglutination inhibition (HI). It is concluded that ECMS has potential to improve the immune responses and deserve further study as an adjuvant.
Agriculture ; methods ; Animals ; Chickens ; Drug Combinations ; Drug Synergism ; Drugs, Chinese Herbal ; administration & dosage ; Influenza A Virus, H5N1 Subtype ; drug effects ; Influenza Vaccines ; administration & dosage ; Influenza in Birds ; prevention & control ; Magnoliopsida ; chemistry ; Poultry Diseases ; prevention & control ; Seeds ; chemistry ; Treatment Outcome ; Vaccination ; methods

To evaluate the immunities of biodegradable microsphere as a release delivery system for DNA vaccine against Infectious Bursal Disease Virus, in our study, silk fibroin/chitosan microsphere adjuvant was prepared with a precipitation/coacervation method. Both glutaraldehyde and Na2SO4 solution were used in cross-linking. No immune chicken were intramuscularly inoculated at 14 day-old and boosted 2 weeks later. The results show that glutaraldehyde destroyed the DNA activity of the vaccine whereas Na2SO4 solution did not. Factors of the chitosan concentration 0.5% (pH 5.0), silk fibroin concentration 0.6%, plasmid DNA (500 microg/mL) dissolved in 2% Na2SO4 solution were optimized to produce microsphere, with a loading capacity of 89.14%. The average particle size of SF-CS/pCI-VP2/4/3 microsphere is 1.98 microm, and it can protect the loading DNA vaccine from DNase I digestion. Data from anti IBDV ELISA antibodies in the serum show that immunization activity of the microsphere groups were generally higher than plasmid vaccine group (P < 0.05), and the SF/CS compound microspheres group was better than that of sole CS microsphere group. The developed SF/CS microspheres are a very promising vaccine delivery system.
Adjuvants, Immunologic ; chemistry ; Animals ; Birnaviridae Infections ; prevention & control ; veterinary ; Chickens ; Chitosan ; chemistry ; Fibroins ; chemistry ; Infectious bursal disease virus ; Microspheres ; Plasmids ; Poultry Diseases ; prevention & control ; Vaccines, DNA ; chemistry ; Viral Vaccines ; chemistry

In order to determine immunogenicity and protective effect in chickens, we used the IBDV (Infectious bursal disease virus)-Vp2/Lactobacillus casei as antigen transfer system. First, the immunized and control chickens were challenged by IBDV/DQ at lethal dose to determine the protective ratio. Second, chickens were orallyand intranasally vaccinated twice with 10(9) CFU/mL pLA-VP2/L. casei, pLA/L. casei and PBS as negativecontrol and commercial vaccine as positive control. The bursa injury and the lesion score wererecorded post challenge. The level of specific IgG and sIgA in pLA-VP2/L. casei and positive control groups was significantly higher than that in negativecontrol groups. The protection efficacy in pLA-VP2/L. casei oral group was higher than that inintranasal group. The SI. of pLA-VP2/L. casei oral group was significant higher than other groups. The lesion score indicated the pLA-VP2/L. casei was safer than commercial vaccine for bursa. Collectively, the pLA-VP2/L. casei could be a vaccine candidate for IBDV.
Animals ; Antibodies, Viral ; blood ; Antibody Formation ; Birnaviridae Infections ; prevention & control ; veterinary ; Chickens ; Infectious bursal disease virus ; Lactobacillus casei ; Poultry Diseases ; prevention & control ; Recombinant Proteins ; immunology ; Viral Structural Proteins ; immunology ; Viral Vaccines ; immunology

The entire S1 protein gene of five infectious bronchitis (IB) vaccine strains (JAAS, IBN, Jilin, J9, H120) used in China were compared with that of the IB field isolate CK/CH/LDL/97 I present in China. The nucleotide and deduced amino acid similarities between the five IB vaccine strains and the field strain, CK/CH/LDL/97 I, were not more than 76.4% and 78.7%, respectively. Phylogenetic analysis based on the S1 gene showed that the vaccine strains and the field strain belonged to different clusters and had larger evolutionary distances, indicating that they were of different genotypes. The five vaccine strains were used for protection test against challenge of the field isolate CK/CH/LDL/97 I. The chickens inoculated with five vaccine strains showed morbidity as high as 30%-100% after challenged with the CK/CH/ LDL/97 I strain. The organ samples at 5 days post challenge showed that the viral detection rates were 50%-90% and 10%-30% for trachea and kidney, respectively. The live attenuated vaccines only provided partial protection to the vaccinated chickens against heterologous IBV infection, CK/CH/LDL/97 I.
Animals ; Antibodies, Viral ; blood ; Chickens ; virology ; Coronavirus Infections ; prevention & control ; veterinary ; Infectious bronchitis virus ; classification ; genetics ; immunology ; isolation & purification ; Membrane Glycoproteins ; genetics ; Phylogeny ; Poultry Diseases ; prevention & control ; Spike Glycoprotein, Coronavirus ; Vaccines, Attenuated ; immunology ; Viral Envelope Proteins ; genetics ; Viral Vaccines ; immunology

The protective efficacy of DNA plasmids encoding avian infectious bronchitis virus (IBV) S1, N, or M protein was investigated in chickens. Chickens were inoculated monovalently (with plasmid pVAX1-16S1, pVAX1-16M, or pVAX1-16N alone) or multivalently (combination of the three different plasmids, pVAX1-16S1/M/N). A prime-boost immunization protocol against IBV was developed. Chickens were immunized with the multivalent DNA vaccine twice and then boosted with an inactivated vaccine once. Antibody titers of the chickens immunized with pVAX1-16S1/M/N were much higher than those of the monovalent groups (p < 0.01). A protective rate up to 90% was observed in the pVAX1-16S1/M/N group. The serum antibody titers in the prime-boost birds were significantly higher than those of the multivalent DNA vaccine group (p < 0.01) but not significantly different compared to the inactivated vaccine group at 49 days of age. Additionally, the prime-boost group also showed the highest level of IBV-specific cellular proliferation compared to the monovalent groups (p < 0.01) but no significant difference was found compared to the multivalent DNA vaccine group, and the prime-boost group completely protected from followed viral challenge.
Aging ; Animals ; Antibodies, Viral/blood ; Cell Proliferation ; Chickens ; Coronavirus Infections/prevention & control/*veterinary/virology ; Immunization, Secondary/veterinary ; Infectious bronchitis virus/*immunology ; Poultry Diseases/*prevention & control/virology ; T-Lymphocyte Subsets/cytology/physiology ; Vaccines, DNA/immunology ; Vaccines, Inactivated/immunology ; Viral Vaccines/*immunology

Protective immune response of the available IBD vaccine is insufficient to fully protect against the prevailing strain of the infectious bursal disease virus (IBDV). Such a vaccination escape IBDV field isolate idenfied from Anhui province of China in December 2007, where IBD broke out at 2 weeks post vaccination. The IBDV vp2 gene was cloned into pFastBacHTA donor plasmid, followed by generation of the recombinant bacmid DNA pBac-VP2. The latter was used to transfect insect cell Sf9 with Lipofectamine to produce recombinant baculovirus vBac-VP2. The Sf9 cells infected with vBac-VP2 were stained positive against IBDV antibody using the indirect immunofluorescence assay (IFA), which was also confirmed by the detection of IBDV Vp2 protein in the infected Sf9 cells by IBDV sandwich ELISA. Western blotting revealed that the calculated protein of approximately 53 kDa was in the expressed in the insect cells. Moreover, virus-like particles (VLPs) and "inclusion body-like"structure in the infected Sf9 cells were observed under electron microscopy. We further developed an indirect ELISA for the detection of the IBDV antibodies, which was specific and sensitive. In addition, the lysates of vBac-VP2 infected cells was used to immunize 2-week-old SPF chickens, followed by challenging with the virulent IBDV, the survival rate was 30% at 14 days post primary immunization, however, the survival rate was 100% at 14 d after the booster vaccination. The ELISA antibody titers was up to 3.2 x 10(3) and neutralization antibody titer was 2536, significantly higher than those of one-shot vaccination, 8 x 10(2) and 1106, respectively. The immunized chickens did not show any clinical signs and histopathological changes of infection in 7-days trial time. The bursa/body-weight ratios were higher than those of the unimmunized control (P < 0.05). The virus-like-particle recombinant Vp2 protein expressed in insect cells promises to be a novel subunit vaccine and diagnostic reagent candidate for IBDV.
Animals ; Baculoviridae ; genetics ; Cell Line ; Chickens ; Infectious bursal disease virus ; immunology ; Insecta ; genetics ; metabolism ; Poultry Diseases ; prevention & control ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; Viral Structural Proteins ; biosynthesis ; genetics ; Viral Vaccines ; immunology