• Journal of Veterinary Clinics
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• v.15 no.1
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• pp.46-55
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• 1998

This study was performed to verify the effect of modified live virus vaccine against canine parvovirus (CPV) infection. Serum hemagglutination inhibition (Hl) test, histopathological and immunohistochemical techniques and polymerase chain reaction were used. The results were as follows: 1. During the experimental terms after vaccination, serum Hl titer was stable. Geometric mean titer (GMT) after the 1st vaccination was 280. After virulent CPV was challenged, GMT was 1,306. 2. After challenge by virulent CPV, the vaccinated group was not shown clinical signs and gross and histopathological findings. 3. After challenge by virulent CPV, the vaccinated group was not detected viral antigens in the small intestine immunohistochemically. 4. After challenge by violent CPV, the vaccinated group was not shown virus shedding in feces. In conclusions the overall results confirmed that modified live virus vaccine was effective on prevention of canine parvovirus infection.

• Pediatric Infection and Vaccine
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• v.4 no.1
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• pp.116-125
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• 1997

Purpose : Studies on the duration of immune response against Japanese encephalitis virus from recipients with JE vaccine (Nakayama-NIH strain) in Korea. Methods : To determinate the immune response and the duration of antibody against JE vaccine, 213 students were examined since 1994 using hemmaglutination inhibition test and plaque reduction neutralization test (PRNT). Results : 24 months after the first vaccination, haemmaglutination inhibition and neutralizing antibody maintained from the recipients 63.4% (>1:20) and 100% (>1:20), respectively. In April 1996, one dose booster to the same recipients those who were vaccinated in 1994, the GMT antibody for HI and PRNT titer were both increased from 1:11.6 to 1:13.2 and 1:275.7 to 1:348.1, respectively, after 6 months booster (after 30 months from the initial vaccination). This results showed that the antibody from the active immunity could be maintained more than 12 months after the initial vaccination. On the basis of these results, inactivated killed JE vaccine (Nakayama-NIH strain) using for preventing against JE purpose seems to produce antibody enough to protect against JE at present. Conclusions : Along with the results of this study demonstrating duration of antibody, the active immunization could be maintained as long as by initial vaccination of 2 doses, a single dose of booster vaccination made during a period of 1 month to 12 months and the successive booster vaccination by 2 or 3 year intervals. However, the immunization schedule should be concerned with both epidemiology of disease and the immune response of vaccinated individuals.

• Korean Journal of Veterinary Research
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• v.63 no.1
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• pp.5.1-5.9
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• 2023

Feline panleukopenia virus (FPV), feline calicivirus (FCV), and feline herpesvirus type-1 (FHV-1) are major infectious pathogens in cats. We evaluated the immunogenicity of a new vaccine containing inactivated FPV, two FCVs, and FHV-1 in animals. An FPV, two FCVs, and an FHV-1 isolate were continuously passaged 70, 50, 80, and 100 times in CRFK cells. FP70, FC50, FC80, and FH100 were propagated and used as vaccine antigens. Two inactivated feline virus vaccines, feline rehydragel-adjuvanted vaccine (FRAV) and feline cabopol-adjuvanted vaccine (FCAV) were prepared and inoculated into mice and guinea pigs. Humoral immune responses were measured using hemagglutination inhibition (HI) for FPV and virus-neutralizing antibody (VNA) for two FCVs and FHV-1 tests. Serial passages in CRFK cells resulted in increase in titers of FPV and two FCVs but not FHV-1 The FCAV induced higher mean HI and VNA titers than the FRAV in guinea pigs; therefore, the FCAV was selected. Cats inoculated with FCAV developed a mean HI titer of 259.9 against FPV, and VNA titers of 64, 256, and 3.2 against FCV17D03, FCV17D283, and FHV191071, respectively. Therefore, cats inoculated with the FCAV showed a considerable immune response after receiving a booster vaccination.

• Journal of Veterinary Clinics
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• v.23 no.4
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• pp.416-420
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• 2006

Compare to testing sera individually, pooled-serum testing has considered as a cost-effective method, particularly on a large population-based seroprevalence studies. This study was to determine the relationship between individual sera and pooled sera titers for detection of avian infectious bronchitis virus (IBV) and to evaluate suitability of pooled sera by comparing prevalences estimated from both samples. A total of 5,000 individual samples were collected from 500 flocks in Chungcheong, Gyunsgi, and Kangwon provinces between January 2005 and February 2006. Ten samples were randomly selected from each flock. Five-hundred pooled sera were prepared by mixing equal amount of each 10 individual serum from the original samples. IBV antibody titers were measured by hemagglutination inhibition (HI) test. The least squares regression analysis was performed to construct equation between pooled and mean individual titers. To determine whether the flock is infected 4 arbitrary criteria were used: detection of at least 1 chicken with HI titer ${\ge}$ 9 (criterion 1), detection of at least 2 samples with HI titer ${\ge}$9 (criterion 2), detection of at least 1 sample with HI titer ${\ge}$ 10 (criterion 3), and filially detection of at least 1 sample with HI titer ${\ge}$ 11 (criterion 4). The receiver operating characteristic (ROC) curve was used to examine the cut-off points of pooled titers showing optimal diagnostic accuracy. The area under the curve (AUC), sensitivities (Se), specificities (Sp), and positive (PPV) and negative (NPV) predictive values were calculated. The regression equation between pooled titers (pool) and mean individual titers (mean) was: $pool= 1.2498+0.8952{\times}mean$, with coefficient of determination of 87% (p< 0.0001). The optimal cut-off points of pooled titers were titer 8 for criterion 1 (AUC=0.975, Se=0.883, Sp=0.959, PPV=0.985, NPV=0.728), titer 8 for criterion 2 (AUC=0.969, Se=0.954, Sp=0.855, PPV=0.926, NPV=0.907), titer 9 for criterion 3 (AUC=0.970, Se=0.836, Sp=0.967, PPV=0.978, NPV=0.772), and titer 9 for criterion 4 (AUC= 0.946, Se=0.928, Sp=0.843, PPV=0.857, NPV=0.921). The difference of 'prevalence estimated by individual and pooled sample showed a minimum of 2% for criteria 2 and a maximum of 9.1:% for criteria 3. These results indicate that the use of pooled sera in HI test for screening IBV infection in laying hen flocks is considered as a cost-effective method of testing large numbers of samples with high diagnostic accuracy.

• Korean Journal of Veterinary Research
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• v.46 no.3
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• pp.215-224
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• 2006

In order to search the availability of the lectin extracted from Korean mistletoe(Viscum album coloratum) as an adjuvant for the avian vaccines, attempts were made to determine toxicity of the lectin in chicks and its immunostimulating activity on the inactivated vaccines against Newcastle disease virus(NDV). For the determination of toxicity, the lectin was injected into the thigh muscle of SPF chicks(Charles River) of 1-week-old and observed hematologically and pathologically. For the determination of immunostimulating effects, lectin-adjuvanted, inactivated NDV vaccines were injected into the thigh muscle of SPF chicks in the same age group. Sera of the chicks were examined for the hemagglutination-inhibition(HI) antibodies induced, their HI titers and reaction to the NDV antigens. The data were further compared with those from aluminum hydroxide [$Al(OH)_3$]-adjuvanted vaccines and vaccines without adjuvant, and the results are as follows. There were no significant changes observed in the values of RBC, WBC, Hb, PCV, MCV, MCH, MCHC, AST, ALT, BUN, creatinine and total proteins in the chicks administered with lectin of 1.1, 2.2 and $22.2{\mu}g/kg$ body weight, which means the lectin has no effects on blood values and functions of liver and kidney. In histopathologic observation, no lesions were observed in the brain, heart, liver, lung, spleen, kidney, thymus and bursa of Fabricius of the chicks administered with lectin of 1.1, 2.2 and $22.2{\mu}g/kg$ body weight. There were inflammatory lesions, such as congestion, hemorrhage, edema, infiltration of macrophages and coagulation necrosis observed in the thigh muscle of chicks administered with lectin of $22.2{\mu}g/kg$ body weight, whereas no changes were observed in 1.1 and $22.2{\mu}g/kg$ lectin administered chicks. In chicks immunized with lectin($4.4{\mu}g/kg$ of body weight)-adjuvanted B1, LaSota and Ulster 2C vaccines, HI titers in reciprocal values for $log_2$ were 1.8-2.2 at 1 week after vaccination, which was similar with those of 1.5-2.9 by $Al(OH)_3$-adjuvanted vaccines. The HI titers by the lectin-adjuvanted vaccines reached to 3.9-5.3 at 4 weeks, whereas those by the $Al(OH)_3$-adjuvanted vaccines were more high as 7.3-9.3. Meanwhile, the immunostimulating effects of the lectin were recognized while compared to the HI titers with 2.4-3.7 in chicks immunized with vaccines without adjuvants at 4 weeks after vaccination. The chicks immunized with lectin-adjuvanted vaccines were enough to resist challenges by Kyojeongwon strain, a very virulent NDV at 4 weeks after vaccination as well as chicks immunized with $Al(OH)_3$-adjuvanted vaccines. The HI titers by the lectin-adjuvanted vaccines reached to high level as 8.7-10.3 as those with 8.2-9.6 by the $Al(OH)_3$-adjuvanted vaccines at 6 weeks after vaccination, which may be the booster effects by the challenge virus. Antibodies specific to the HN and F antigens of NDV were observed in the sera of both chicks immunized with lectin-adjuvanted vaccines and $Al(OH)_3$-adjuvanted vaccines.

• Korean Journal of Veterinary Research
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• v.42 no.4
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• pp.523-529
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• 2002

A Total of 703 swine sera from 55 swine farrns (Mar. 1998 through Feb. 2001) were nation-wide collected for the presence of the antibody to influenza A virus H3 subtype isolate. The presence of antibody was tested by hernagglutination inhibition with chicken red blood cells and seropositiveness was determined by HI titer ${\geq}1$: 40. Sero-prevalence was evaluated based on year, season, region and age, respectively. In consequence, there were seme differences by year, season and region, respectively. High susceptibility was routinely observed in 60 and 90 day-old piglets. Therefore, it seems that the sero-prevalence to swine influenza virus H3 subtype isolate is useful for the prevention and control of swine influenza in Korea.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.4
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• pp.465-470
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• 2009

The chicken Mx gene has been regarded as a candidate gene for resistance to avian influenza virus (AIV). In this study, three groups of chickens with homozygotes (AA, GG) and heterozygotes (AG) of the resistant (A) and susceptible alleles (G) to AIV of the Mx gene were constructed from a line of dwarf egg-type chickens. These chickens were not examined for their resistant activities to AIV because the differential resistance had only been detected in vitro. The birds of the three groups were vaccinated with inactivated H5N2 AIV vaccine and the level of hemagglutination inhibition (HI) antibody to AIV was detected. The association between disease resistant activity to AIV and antibody response to AIV vaccination in the three groups was analyzed. The chickens with homozygous resistant allele A showed the lowest antibody levels, whereas the heterozygous chickens (AG) presented the highest antibody level after the boosting vaccination, which indicates that the efficiency of artificial selection on the resistant allele of Mx gene will be compromised since the homozygotes of the allele presented the weakest antibody response to the corresponding vaccine.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.2
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• pp.231-235
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• 1996

Bangladeshi indigenous chickens of mixed ages vaccinated twice at a three week interval with either conventional vaccines-$F_1$ (ocular) and M (mukteswar, Intramuscular), or heat resistant $V_4$ vaccine administered by either the ocular or oral routes, all showed satisfactory hemagglutination inhibition antibody (HI) responses and protection against Newcastle Disease (NCD) challenge persisting for four months. The antibody response to $F_1$ and M was higher than for $V_4$, which was similar whether administered by the ocular or oral routes. All vaccinated treatments have a significant level of protection compare to the control group (p<0.01). No significant difference (p>0.05) in the protection against controlled challenge with virulent NCD virus was found between vaccinated groups.

• Korean Journal of Veterinary Service
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• v.33 no.3
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• pp.213-221
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• 2010

The results from a total of 412 blood samples consisted of 187 samples from regular visiting group (RV), 94 samples from first visiting group (FV), 52 samples from abandoned group (A), 54 samples from special breeder group (SB), and 25 samples from preliminary breeder group (PB) showed that RV(94.7%) and SB(88.9%) groups had the higher levels of protective antibody, but PB (36.0%) group revealed the lowest level. Among 96 blood samples with lower protective antibody levels, 14 samples (14.6%), 72 samples (75.0%) and 10 samples (10.4%) were below the protective antibody levels to distemper/parvo-virus, distemper only and parvovirus only, respectively. These results implied that antibody to parvovirus was well generated than that to distemper. Eighty six samples (20.9%) showed the protective antibody titer under 1:96 to distemper and 24 samples (5.8%), the protective antibody titer under 1:40 to parvovirus.

• Journal of Veterinary Clinics
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• v.24 no.4
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• pp.603-607
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• 2007

The sample sizes required to detect at least one chicken infectious bronchitis virus(IBV) infection at flock-level were determined using pooled samples for 48 submissions with different samples in each. A total of serum samples of 9,980 layers from Kangwon, Chungpook and Chungnam province were collected and tested hemagglutination inhibition(HI) antibody titers against IBV both individually and with pooling size of 10. Of the 48 submissions, 72.9% were required less than 5 pools to detect at least one infected pool at 95% confidence level, and the corresponding rate was 77.1% at 90% confidence level. Overall, the number of pools was decreased as the percent of positive pools increased. At two different cut-of HI titer${\geq}9\;and{\geq}10$ for individual samples the seroprevalence was 50.1% and 33.4%, respectively while 59.9% were seropositive for pooled samples at HI $titer{\geq}8$. The correlation coefficients between pooled and individual samples at each submission were 0.592(p<0.001) for HI $titer{\geq}9$ and 0.561(p<0.001) for ${\geq}10$, with common correlation coefficient of 0.576. This study indicated that pooled testing for the detection of IBV infection may be an alternative strategy when only the pooled results are of interest and the prevalence has not known exactly.