In order to observe the effect of the immune and weight of chickens after use the attenuated vaccine with low dose of chicken infectious anemia virus (CIAV). In this study, the effects of low dose of CIAV on the weight of SPF chickens and NDV antibody production were observed by simulated experiments. The results showed that 10 EID50 and 5 EID50 CIAV per plume attenuated NDV vaccines were used to cause the weight loss of SPF chickens. Compared with the use of the non contaminated vaccine group, it has significant difference. And NDV antibody levels compared with the use of the non contaminated groups also decreased after use the vaccine with two doses of CIAV contaminated. It has significant difference. A certain proportion of CIAV antibody positive was detected at the beginning of the second week after use the NDV vaccine with two doses of CIAV contaminated. The detection of a high proportion of CIAV nucleic acid was detected in the first week after the use of a contaminated vaccine. The results of the study demonstrate the effects of CIAV pollution on the production and immune function of SPF chickens, and it is suggested that increasing the detection of viral nucleic acid can help save time and improve the detection rate in the detection of exogenous virus contamination by SPF chicken test method.
Animals ; Antibodies, Viral ; immunology ; Chicken anemia virus ; genetics ; immunology ; physiology ; Chickens ; Circoviridae Infections ; immunology ; veterinary ; virology ; Poultry Diseases ; immunology ; virology ; Specific Pathogen-Free Organisms ; Vaccines, Attenuated ; administration & dosage ; genetics ; immunology

Salmonella enterica Gallinarum (SG) causes fowl typhoid (FT), a septicemic disease in avian species. We constructed deletion mutants lacking the stress sigma factor RpoS, the nitric oxide (NO)-detoxifying flavohemoglobin Hmp, and the SsrA/SsrB regulator to confirm the functions of these factors in SG. All gene products were fully functional in wild-type (WT) SG whereas mutants harboring single mutations or a combination of rpoS, hmp, and ssrAB mutations showed hypersusceptibility to H2O2, loss of NO metabolism, and absence of Salmonella pathogenicity island (SPI)-2 expression, respectively. A triple-deletion mutant, SGDelta3 (SGDeltarpoSDeltahmpDeltassrAB), was evaluated for attenuated virulence and protection efficacy in two-week-old Lohmann layer chickens. The SGDelta3 mutant did not cause any mortality after inoculation with either 1 x 10(6) or 1 x 10(8) colony-forming units (CFUs) of bacteria. Significantly lower numbers of salmonellae were recovered from the liver and spleen of chickens inoculated with the SGDelta3 mutant compared to chickens inoculated with WT SG. Vaccination with the SGDelta3 mutant conferred complete protection against challenge with virulent SG on the chickens comparable to the group vaccinated with a conventional vaccine strain, SG9R. Overall, these results indicate that SGDelta3 could be a promising candidate for a live Salmonella vaccine against FT.
Administration, Oral ; Animals ; Bacterial Proteins/*genetics/immunology ; *Chickens ; Female ; Poultry Diseases/*immunology/microbiology ; Salmonella Infections, Animal/*immunology/microbiology ; Salmonella Vaccines/administration & dosage/genetics/*immunology ; Salmonella enterica/immunology/*physiology ; Vaccines, Attenuated/administration & dosage/genetics/immunology ; Virulence

The application of the cholera vaccine is one of the cholera prevention and control strategies. Cholera vaccines stimulate mucosal immune to play the role of antibacteria and antitoxin. When the cholera toxin B subunit is added in the cholera vaccine, it could also defend against some diarrhea associated pathogens by cross-protection. Oral inactivated cholera vaccines are commercially available now. The oral live vaccine candidates are under development. The development of cholera vaccine is not only on the technical aspect, based on the situations of epidemic areas and population, cost, storage and transportation condition should also be considered. Though the argument on the use of cholera vaccine in epidemic areas and population in high risk existed previously, its vaccination has reached agreement now based on the clinical trials and evaluations during epidemic period.
Administration, Oral ; Cholera ; Cholera Toxin ; Cholera Vaccines ; Cross Protection ; Diarrhea ; Humans ; Vaccination ; Vaccines, Attenuated ; Vaccines, Inactivated

OBJECTIVETo evaluate safety of different sequential immunization schedules of inactivated poliovirus vaccine (IPV) and oral poliovirus vaccine (OPV) primary vaccination.

METHODSInfants of 2 months old (60-89 days) selected in Beijing, were assigned to four groups, 1 dose IPV plus 2 doses OPV (I-O-O), 2 doses IPV plus 1 dose OPV(I-I-O), 3 doses IPV (I-I-I), and 3 doses OPV (O-O-O), and were vaccinated at the age of 2, 3, 4 months, from 2009 to 2011. The frequencies of systemic as well as local injection site reactions after every dose were recorded and calculated. A total of 553 infants were enrolled in the study and 89 infants were quit, 1492 diseases were observed.

RESULTSThe incidence of adverse events in I-O-O, I-I-O, I-I-I, O-O-O were 22.9% (94/410), 18.4% (60/327), 22.0% (78/354) and 17.7% (71/401) with no statistical differences (χ(2) = 4.84, P = 0.184). Dose 1 (22.7% (32/141)-35.3% (54/153) ) was more frequently than dose 2 and dose 3. No serious adverse events (SAE) were reported during the study. The incidence of systemic adverse reactions in I-O-O, I-I-O, I-I-I, O-O-O were 21.5% (88/410), 17.7% (58/327) , 20.1% (71/354) and 17.7% (71/401) with no statistical differences (χ(2) = 2.53, P = 0.472). Abnormal crying were the most frequency reactions (7.2% (29/401)-11.3% (37/327) ) in 4 groups. Rarely severe reactions were observed of abnormal crying, somnolence, irritability and mild or medium reactions occurred in other symptoms. Local adverse reactions such as injection site pain, scleroma and swelling were reported by 2.2% (5/229)-5.6% (22/393) ,0-0.9% (2/229) and 0-1.0% (4/393) in I-O-O,I-I-O and I-I-I, and most reactions were mild.

CONCLUSIONThree IPV immunization and IPV/OPV sequential immunization as well as three OPV immunization demonstrated safe.

Humans ; Immunization Schedule ; Infant ; Poliovirus Vaccine, Inactivated ; administration & dosage ; adverse effects ; Vaccines, Attenuated ; administration & dosage ; adverse effects

OBJECTIVETo evaluate immunogenicity after primary vaccination by different sequential program of inactivated poliovirus vaccine (IPV) and oral poliovirus vaccine (OPV).

METHODSChildren of 2 months old (60-89 days) selected in Beijing were assigned to 4 groups, 1 dose IPV plus 2 doses OPV (I-O-O, 122 children), 2 doses IPV plus 1 dose OPV(I-I-O, 103 children), 3 doses IPV (I-I-I, 114 children), and 3 doses OPV (O-O-O, 106 children), and were vaccinated at the age of 2, 3, 4 months. Polio neutralizing antibody titers against poliovirus types 1, 2, and 3 were tested and protective rates were calculated before the 1st dose, after the last dose, and after the 1st and 2nd dose of IPV.

RESULTSAfter the primary immunization, geometric mean titers (GMT) of polio neutralizing antibody titers against poliovirus types 1, 2, and 3 were 788.32, 738.42 and 631.17 in O-O-O group, 212.02, 262.30 and 537.52 in I-I-I group, 940.35, 929.72 and 940.35 in I-O-O group and 901.09, 1102.68 and 1110.12 in I-I-O group (F values were 47.71, 53.84, and 9.81 respectively, all P values<0.01). The protective rate of three types among each group was 98.1% (104/106)-100.0% and the difference was not statistically significant (P>0.05). After the 1(st) dose of IPV, the GMT were 18.88, 37.77, 24.64 and the protective rate was 82.6% (122/138)-96.4% (133/138); after the 2nd dose of IPV, GMT were 177.03, 168.25, 321.86 and the protective rate was 99.1% (108/109)-100.0% (109/109) in antibody types 1, 2 and 3, respectively.

CONCLUSIONGMT of polio neutralizing antibody titers against poliovirus is higher after vaccination by sequential program of IPV and OPV than that by IPV or OPV 3-doses program. High level of protective rate after 2 doses of IPV in I-I-O group may lead to better protection from vaccine associated paralytic poliomyelitis (VAPP). Sequential program of IPV and OPV can be used to maintain high level of herd immunity and to prevent VAPP, and the I-I-O sequential program should be the first choice.

Humans ; Immunization Schedule ; Infant ; Poliovirus Vaccine, Inactivated ; administration & dosage ; immunology ; Poliovirus Vaccine, Oral ; administration & dosage ; immunology ; Vaccines, Attenuated ; immunology

The threshold hypothesis of attenuated lentiviral vaccine considers that the type of host response to infections of lentiviruses depends on the viral load. To evaluate the correlation between viral loads of the attenuated vaccine strain of equine infectious anemia virus (EIAV) and their effects to induce protective immunity, longitudinal plasma viral loads in groups of horses inoculated with either an attenuated EIAV vaccine strain (EIAV(DLV125)) or sub-lethal dose of an EIAV virulent strain (EIAV(LN40)) were compared. Similar levels of plasma viral loads ranging from 10(3)-10(5) copies/mL were detected from samples of these two groups of animals (P > 0.05) during 23 weeks post the inoculation. However, different responses to the challenge performed thereafter with lethal dose of the EIAV virulent strain were observed from the groups of horses inoculated with either EIAV(DLV125) or sub-lethal dose of EIAV(LN40). The protective efficiency was 67% (3 of 4 cases) and 0 (none of 2 cases), respectively. Our results implicate that the viral load of EIAV attenuated vaccine is not the primary factor, or at least not the solo primary factor, to determine the establishment of immune protection.
Animals ; Equine Infectious Anemia ; blood ; immunology ; prevention & control ; Horses ; Immunization ; methods ; Infectious Anemia Virus, Equine ; immunology ; pathogenicity ; RNA, Viral ; blood ; genetics ; Random Allocation ; Reverse Transcriptase Polymerase Chain Reaction ; Time Factors ; Vaccines, Attenuated ; administration & dosage ; immunology ; Viral Load ; Viral Vaccines ; administration & dosage ; immunology ; Virulence ; immunology

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is an important pathogen. One of the important virulence traits of EHEC O157:H7 is the capacity to produce attaching and effacing (A/E) lesions on enterocyte. This property encoded by a pathogenicity island termed the locus of enterocyte effacement (LEE). LEE contains ler (LEE-encoded regulator) gene. The product of ler is a central up-regulator of many virulence genes of the LEE. Another important virulence factor of EHEC O157: H7 is Shiga toxin (Stx), encoded by a prophage integrated into the chromosome of O157:H7. In order to obtain an attenuated vaccine candidate, a ler deletion mutant of O157: H7 was constructed by use of suicide vector pCVD442. Meanwhile, due to potential instability of the prophage carrying the stx gene, the prophage was cured with serial passages of bacteria and confirmed by PCR and DNA sequencing. A ler/stx deletion mutant of EHEC O157:H7 was constructed, termed as O157:H7(deltaler/deltastx). The cultural supernatant of O157 ler/stx deletion mutant was inoculated in vero cell culture, and the result indicating that O157 ler/stx deletion mutant lost the toxigenicity to vero cell. Test group and control group of mice were orogstrically inoculated with the O157 ler/stx deletion mutant and the virulent strain O157:H7 EDL933, respectively. Mice were observed daily for clinical signs and weight changes. After inoculation of the deletion mutant, test group of mice (inoculated with O157:H7(deltaler/deltastx)) gained weight normally and experienced no clinical signs. In contrast, control group of mice (inoculated with O157: H7) exhibited weight loss and all died in four days. In another experiment, pregnant mice were orally vaccinated by O157:H7(deltaler/ deltastx) twice at interval of 14 days. Subsequently, the suckling mice were orally challenged with O157:H7 EDL933 at 7 days of age. The results showed that 78.34% of the sucking mice born by vaccinated mice were survival and 12.73% of the sucking mice born by non-vaccinated mice were survival. This study demonstrated that O157 ler/stx deletion mutant lost the toxigenicity to vero cell and to be safety to mice. Oral immunization can induce specific immune responses, and this mutant strain could be used as an attenuated vaccine candidate against EHEC O157.
Administration, Oral ; Animals ; Animals, Suckling ; Antibodies, Bacterial ; blood ; immunology ; Cercopithecus aethiops ; Escherichia coli Infections ; immunology ; mortality ; prevention & control ; Escherichia coli O157 ; genetics ; immunology ; pathogenicity ; Escherichia coli Proteins ; genetics ; Escherichia coli Vaccines ; administration & dosage ; genetics ; immunology ; Female ; Gene Deletion ; Genetic Vectors ; genetics ; Genomic Islands ; genetics ; Immunization ; Lactation ; immunology ; Male ; Mice ; Mutation ; Pregnancy ; Shiga Toxin ; genetics ; Survival Rate ; Trans-Activators ; genetics ; Vaccines, Attenuated ; administration & dosage ; genetics ; immunology ; Vero Cells ; Virulence ; genetics

OBJECTIVETo evaluate the feasibility of oral cytokine gene therapy against tumor using live attenuated Salmonella as a vector.

METHODSA live attenuated AraA- autotrophic mutant of Salmonella typhimurium (SL3261) was used as carrier for eukaryotic expression vectors EGFPN1 and pCMVmIL-12 administered orally in BALB/c and C57BL/6 mice. After 6 weeks, the mice were challenged with 4T1 or Lewis tumor cells, respectively, and flow cytometry and confocal microscopy were used to detect the expression of green fluorescence protein (GFP) in the tissues. PCR and ELISA were performed to detect the integration and expression of mIL-12 gene, and the survival time of the mice was also recorded.

RESULTSGFP expression and mIL-12 gene integration could be detected in the liver, spleen, intestinal, kidney and tumor tissues of the mice. The serum level of mIFN-gamma, mIL-12 increased significantly in mice with oral mIL-12 administration (P<0.05), which resulted in the survival prolongation of the mice as compared with the control mice (P<0.05).

CONCLUSIONOral gene therapy using live attenuated Salmonella can be potentially a simple, effective and above all, safe means for tumor treatment.

Administration, Oral ; Animals ; Carcinoma, Lewis Lung ; therapy ; Flow Cytometry ; Genetic Therapy ; methods ; Genetic Vectors ; administration & dosage ; genetics ; metabolism ; Green Fluorescent Proteins ; genetics ; metabolism ; Interleukin-12 ; genetics ; metabolism ; Mammary Neoplasms, Animal ; therapy ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Microscopy, Confocal ; Neoplasms, Experimental ; therapy ; Salmonella typhimurium ; genetics ; immunology ; metabolism ; Vaccines, Attenuated ; immunology

OBJECTIVETo prepare the live recombinant vaccine of attenuated Salmonella typhimurium SL3261 expressing Helicobacter pylori (H. pylori) B subunit (UreB) and to determine whether it could be used as an oral vaccine against H. pylori infection.

METHODSUsing genomic DNA of H. pylori Sydney strain (SSI) as template, the H. pylori UreB gene fragment was amplified by PCR and subcloned into the expression vector pTC01. The recombinant plasmid pTC01-UreB was then transferred into LB5000 to obtain modified forms, and further conversed into the attenuated Salmonella typhimurium SL3261 to obtain recombinant SL3261/pCT01-UreB as an oral immunization reagent, which was then used to orally immunize Balb/c mice twice at a three-week interval. Twelve weeks later, anti-UreB IgA antibodies in intestinal fluid and IgG antibodies in sera were determined by ELISA. The relating data in control groups (including body weight, gastric inflammation, etc.) were also collected.

RESULTSThe sequencing analysis showed that the UreB gene fragment amplified by PCR was consistent with the sequence of the H. pylori UreB gene. The restriction enzyme digestion revealed that the correct pTC01-UreB was obtained. SDS-PAGE and Western blot showed that a 61KD protein was expressed in SL3261/pTC01-UreB, which could be recognized by anti-H. pylori UreB antiserum and was absent in the control containing only Salmonella typhimurium SL3261 strain. The multiple oral immunization with SL3261/pTC01-UreB could significantly induce H. pylori specific mucosal IgA response as well as serum IgG responses. IFN-gamma and IL-10 levels were significantly increased in SL3261/pTC01-UreB group, and no obvious side effect and change in gastric inflammation were observed.

CONCLUSIONThe attenuated vaccine of Salmonella typhimurium expressing H. pylori UreB can be used as an oral vaccine against H. pylori infection.

Animals ; Antibodies, Bacterial ; blood ; Bacterial Vaccines ; administration & dosage ; immunology ; Female ; Gene Expression Regulation, Bacterial ; Gene Expression Regulation, Enzymologic ; Helicobacter Infections ; immunology ; prevention & control ; Helicobacter pylori ; enzymology ; genetics ; immunology ; Immunoglobulin G ; blood ; Interferon-gamma ; metabolism ; Interleukin-10 ; metabolism ; Mice ; Mice, Inbred BALB C ; Salmonella typhimurium ; genetics ; immunology ; metabolism ; Urease ; genetics ; immunology ; metabolism ; Vaccines, Attenuated ; genetics ; immunology ; Weight Loss

OBJECTIVETo evaluate the efficacy of the interferon alpha-2b nasal spray in prevention of rubella and measles virus infections.

METHODSThe properly selected volunteer groups have been divided into interferon alpha-2b experimental and control group. The experimental group received interferon alpha-2b treatment by nasal spray for 2 days before the immunization, then both groups were challenged with rubella and measles attenuated live vaccine respectively through nasal spray. The sera from pre-immunization and 21 and 28 days after immunization were collected to test the IgG antibody titers. The influence on the viral antibody titer reflects the viral preventive effect by interferon alpha-2b.

RESULTSThe antibody titer difference of measles virus between experimental and control group was 1.26 (21 day) and 2.96 (28 day), there were statistically difference between them; the difference of rubella virus was 0.95 (21 day) and 0.37 (28 day), but there were no statistically differences found.

CONCLUSIONThe preliminary results showed that the interferon alpha-2b can be used as prevention method for measles and rubella viral infections.

Administration, Intranasal ; Adult ; Antibodies, Viral ; blood ; Antiviral Agents ; administration & dosage ; therapeutic use ; Female ; Humans ; Interferon-alpha ; administration & dosage ; therapeutic use ; Male ; Measles ; immunology ; prevention & control ; virology ; Measles Vaccine ; immunology ; therapeutic use ; Measles virus ; drug effects ; immunology ; Recombinant Proteins ; Rubella ; immunology ; prevention & control ; virology ; Rubella Vaccine ; immunology ; therapeutic use ; Rubella virus ; drug effects ; immunology ; Treatment Outcome ; Vaccination ; methods ; Vaccines, Attenuated ; immunology ; therapeutic use ; Young Adult