• Korean Journal of Poultry Science
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• v.18 no.3
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• pp.183-196
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• 1991

In order to establish ELISA method to detect antibody against IBV various factors involved were examined. Antigen was prepared from Massachusetts type IBV which is known to be one of serotypes distributed most widely. The virus was grown in embryonated SPF chicken eggs. Allantoic fluid harvested was processed to ultracentrifugation and sucrose density gradient centrifugation to produce a purified antigen The antisera selected from the field samples based on hemagglutination inhibition test were used as the standard positive and negative sera for this study and the results obtained were summarized as follows. 1 , It was found that ELISA test was satisfactory when the purified antigen was coated on the plate in the amount of about 40ng protein per well. In case of the phospholipase treated hemagglutinating antigen it gave satisfactory results when the each well wns coated with 1.2 to 2.5 hemagglutinating unit which was equivalent to 40 to 90ng of protein. 2. There was no significant difference in the ratio of optical density of positive to that of negative serum whether the coated antigen was held for 1 hour at 37$^{\circ}C$ or it was held overnight at 4$^{\circ}C$. The coated antigen could be kept in dried state without change of antigenecity for at least one month of experimental period at 4$^{\circ}C$. 3. There was a big variation in the optical density and P/N values depending on the maker of the plates and on the plate of the same maker. 4. It was found that background optical density was negligible when serum was diluted more than 1：50 and serum dilution of 1：100 appeared to be appropriate as a routine test dilution to screen the antibody. 5. Optical density was fairly constant 15 minutes afterward from the time substrate was treated and during the 4 hours after stopper was treated. 6. There was a low correlation(r＝0.42) between ELISA and HI test. However, when 74serum samples were tested for the IBV antibody, 98.7% were found to be positive by both tests in which titers of 2$^{6}$ or more by HI test and P/N values of 1.4 or more by ELISA were considered to be positive, 7 Day-old IBV vaccinated chickens shows a similar antibody decay and rising pattern until 8 weeks of age by the two tests, ELISA and HI.

• Pediatric Infection and Vaccine
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• v.19 no.1
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• pp.1-11
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• 2012

Purpose : Although influenza is regarded as one of the major causes of morbidity and mortality in children with cancer, the actual vaccine coverage remains poor. We conducted evaluation of immunogenicity and safety of influenza vaccine in children with cancer. Methods : In this study, 25 children with cancer who received influenza vaccine (SK influenza IX vaccine$^{(R)}$) at the Korea Cancer Center Hospital between October and December 2009 were analyzed. Blood samples of patients were collected twice (at the beginning of this study and at 30th day after vaccination) and their antibody titers were measured using the hemagglutination-inhibition (HI) assay. Immunogenicity of the influenza vaccine was assessed by seroprotection rate on days 0 and 30, seroconversion rate on day 30, and mean fold increase (MFI) of geometric mean titer (GMT) of HI between days 0 and 30. Results : Any of the subjects in our study did not experienced serious adverse events after influenza vaccination. Seroprotection rates were 68% for H1N1, 40% for H3N2, and 36% for B. Seroconversion rates were 12% for H1N1, 16% for H3N2, and 20% for B. MFIs were 0.9 for H1N1, 1.2 for H3N2, and 1.8 for B. Conclusion : In the study, we found a limited protective immune response to influenza vaccine, among subjects with cancer. However, some subjects showed seroconversion, and there were no severe adverse events among all subjects, supporting the recommendation of annual influenza vaccination in children with cancer.

• Journal of Microbiology and Biotechnology
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• v.19 no.10
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• pp.1271-1279
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• 2009

To develop low endotoxic and multi-immunogenic outer membrane vesicles (OMVs), a deletion mutant of the msbB gene in Salmonella enterica serovar Typhimurium (S. Typhimurium) was used as a source of low endotoxic OMV, and an expression vector of the canine parvovirus (CPV) VP2 epitope fused to the bacterial OmpA protein was constructed and transformed into the Salmonella ${\Delta}msbB$ mutant. In a lethality test, BALB/c mice injected intraperitoneally with the Salmonella ${\Delta}msbB$ mutant survived for 7 days, whereas mice injected intraperitoneally with the wild type survived for 3 days. Moreover, all mice inoculated orally with the ${\Delta}msbB$ mutant survived for 30 days, but 80% of mice inoculated orally with the wild type survived. The OmpA::CPV VP2 epitope fusion protein was expressed successfully and associated with the outer membrane and OMV fractions from the mutant S. Typhimurium transformed with the fusion protein-expressing vector. In immunogenicity tests, sera obtained from the mice immunized with either the Salmonella msbB mutant or its OMVs containing the OmpA::CPV VP2 epitope showed bactericidal activities against wild-type S. Typhimurium and contained specific antibodies to the CPV VP2 epitope. In the hemagglutination inhibition (HI) assay as a measurement of CPV-neutralizing activity in the immune sera, there was an 8-fold increase of HI titer in the OMV-immunized group compared with the control. These results suggested that the CPV-neutralizing antibody response was raised by immunization with OMV containing the OmpA::CPV VP2 epitope, as well as the protective immune response against S. Typhimurium in BALB/c mice.

• Korean Journal of Poultry Science
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• v.17 no.3
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• pp.225-232
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• 1990

The immune responses of commercial layer chickens against Newcastle disease (ND) were compared among different administration methods and times of vaccination during 4 weeks of age. A total of 372 day-old chickens were devided into 4 groups of 93 birds each. Each of 3 groups was received a commercially available B$_1$ live vaccine via drinking water, eye instillation or spray method at one, 14 and 28 days of age. One group was used as an unvaccinated control. At two and 4 weeks after each time of vaccination, 15 birds from each group were challenged with virulent ND virus at the dose of 10$^{5}$ EID$_{50}$ per bird to examine the pretection rate. Ten to 15 birds from each group were bled at two weeks intervals from day old to 8 weeks of age to determine hemagglutination inhibition antibody titer. The protection rate was generally low regardless of the times of vaccination although two or more times vaccination gave higher protection than once vaccination. The low protection was considered due to low titer of the vaccine used since the vaccine titer was less than 10$^{2.5}$ EID$_{50}$ per bird. Spray method gave better protection compared to eye instillation of drinking water method which resulted in lowest response. When birds were challenged majority showed clinical signs on ND between 3 and 6 days after challenge. Death occured one or two days after onset of symptoms. Major clinical signs observed were depression (96%), drowsy(90%), anorexia (84%), diarrhoea (29%), difficult breath (15%) and torticollis (10%). Hemorrhagic lesions on post mortem were seen in duodenum (51%), trachea(36%), illeum (13%), ceacal tonsil (11%), proventriculus (10%) and some other organs. When birds were challenged majority showed clinical signs on ND between 3 and 6 days after challenge. Death occured one or two days after onset of symptoms. Major clinical signs observed were depression (96%), drowsy(90%), anorexia (84%), diarrhoea (29%), difficult breath (15%) and torticollis (10%). Hemorrhagic lesions on post mortem were seen in duodenum (51%), trachea(35%), illeum (13%), ceacal tonsil (11%), proventriculus (10%) and some other organs.

• Korean Journal of Poultry Science
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• v.39 no.2
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• pp.97-104
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• 2012

Newcastle disease virus (NDV) infects a variety of birds with a wide range of clinical signs from asymptomatic to severe. During a 10-month period in 2011, a total of 1,024 sera from wild birds including 42 species of birds in 8 orders were collected and the seroprevalence of NDV in wild birds was evaluated by hemagglutination inhibition (HI) test. Evidence of NDV infection was observed in 12.6% (129/1,024) of wild birds with a maximum prevalence reported in Mandarin duck (27.8%, 32/115) followed by Mallard duck (20.8%, 57/274), Spot-billed duck (11.9%, 36/303), Pintail (2.9%, 1/34), Black-tailed gull (2.9%, 1/34), White-fronted goose (1.8%, 1/56) and Common teal (1.4%, 1/69). None of the other 35 species of wild birds were antibody-positive for NDV. Mandarin duck, Mallard duck and Spot-billed duck showed high sero-prevalance of 12.2% to 42% during winter season (November to March). Our results indicate that Mandarin duck, Mallard duck and Spot-billed duck might be natural reservoirs for NDV in Korea and the prevalence of NDV infection in wild birds displayed a seasonal pattern with high prevalence of NDV in winter season (November to March).