• Clinical and Experimental Vaccine Research
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• v.12 no.3
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• pp.240-248
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• 2023

Purpose: We reported a survey-based study assessing the parental intention to vaccinate children of 5 to 7 years old against coronavirus disease 2019 (COVID-19). The aim of this study is to assess factors influencing the parental intention to vaccinate their children against COVID-19. Materials and Methods: This study adopted a cross-sectional design, held at the public health center of Senen district, Jakarta, Indonesia from November 1-30, 2022. The off-line questionnaires were distributed via the school administrator to all eligible parents. Factors associated with intention to vaccinate were analyzed with the regression logistic models. Results: Of the 435 parents in this study, 215 had already vaccinated their children against COVID-19 (49.4%), and the overall intention of the participants to vaccinate was 69.7%. Factors associated with intention to vaccinate the children against COVID-19 were parental employment status, parental COVID-19 vaccine status and concern of contracting COVID-19. Parents who are employed, had completed vaccines with COVID-19 booster vaccine, and had concern of their children contracting COVID-19 were more likely to vaccinate their children (odds ratio [OR], 2.10; 95% confidence interval [CI], 1.22-3.69; p=0.011; OR, 2.15; 95% CI, 1.21-3.83; p=0.013; OR, 2.40; 95% CI, 1.34-4.30; p=0.004, respectively). Concern on the vaccine's side effects was negatively associated with the willingness to vaccinate. Conclusion: This study showed that childhood COVID-19 vaccine only covered half of the population, with parental intentions for childhood COVID-19 vaccination being high, reaching almost two-thirds of the study participants. Factors influencing parental intentions were employment status, parental COVID-19 vaccine status, concerns about COVID-19 and concerns about vaccine side effects.

• Parasites, Hosts and Diseases
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• v.30 no.3
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• pp.201-208
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• 1992

A Theileria sergenti soluble merozoite preparation containing the 29, 34, 35 and 105 KD as the immunodominant polypeptides, was evaluated for efficacy, safety and protectivity in Holstein calves against virulent field tick challenge. The soluble antigens (100 mg/dose) were fortified with either complete or incomplete Freund's adjuvant. Twenty naive calves, aged one month, were subcutaneously inoculated with the preparation and a booster dose was administered 4 weeks later. Twenty additional calves served as controls. Five weeks after the booster dose, vaccinates and uninoculated controls were moved to a pasture, a heavily tick infested area in Cheju-do, Korea. The vaccinates showed negligible change in hematocrit and total RBC count whereas control animals showed significant (p<0.05) hematological changes and associated anemia. Only 30% of vaccinates required chemotherapy after the experiment was terminated. All control animals required chemotherapy and 25% received blood transfusion. The highest percent parasitized erythrocytes in vaccinated cattle was 0.4% as compared with 3.6% among controls during the month of July. A significant difference (p<0.05) was observed in the rate of body weight increase. Significant difFerences were also noted in serum albumin, aspartate aminotransferase, total protein and bilirubin. Significantly more vaccinated cattle maintained normal ranges of hematological and biochemical values as compared with the control group. It is suggested that soluble merozoite T. sergenti antigens may be potential vaccine candidates for developing a genetic vaccine in Korea.

• Journal of fish pathology
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• v.19 no.2
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• pp.165-172
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• 2006

This study was performed to verify the stability and efficacy of Streptococcus iniae formalin killed cells on storage at refrigerator temperature in olive flounder, Paralichthys olivaceus. The vaccines preserved for 6, 12 and 15months showed high stability of potency. The antibody titers and protection efficacy to challenge test were significantly higher in booster immunized groups than prime immunized groups during storage. Especially, above 60% of relative percent survival obtained at low antibody revel in prime immunized groups indicates that innate and non-specific immune system might act against the S. iniae challenged.

• Genomics & Informatics
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• v.20 no.2
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• pp.22.1-22.9
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• 2022

The rise of newer coronavirus disease 2019 (COVID-19) variants has brought a challenge to ending the spread of COVID-19. The variants have a different fatality, morbidity, and transmission rates and affect vaccine efficacy differently. Therefore, the impact of each new variant on the spread of COVID-19 is of interest to governments and scientists. Here, we proposed mathematical SEIQRDVP and SEIQRDV3P models to predict the impact of the Omicron variant on the spread of the COVID-19 situation in South Korea. SEIQEDVP considers one vaccine level at a time while SEIQRDV3P considers three vaccination levels (only one dose received, full doses received, and full doses + booster shots received) simultaneously. The omicron variant's effect was contemplated as a weighted sum of the delta and omicron variants' transmission rate and tuned using a hyperparameter k. Our models' performances were compared with common models like SEIR, SEIQR, and SEIQRDVUP using the root mean square error (RMSE). SEIQRDV3P performed better than the SEIQRDVP model. Without consideration of the variant effect, we don't see a rapid rise in COVID-19 cases and high RMSE values. But, with consideration of the omicron variant, we predicted a continuous rapid rise in COVID-19 cases until maybe herd immunity is developed in the population. Also, the RMSE value for the SEIQRDV3P model decreased by 27.4%. Therefore, modeling the impact of any new risen variant is crucial in determining the trajectory of the spread of COVID-19 and determining policies to be implemented.

• Korean Journal of Veterinary Service
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• v.43 no.2
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• pp.89-97
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• 2020

This study was carried out to examine a novel inactivated Salmonella Typhimurium (S. Typhimurium) vaccine candidate for protection of mice against salmonellosis by immunization of BALB/c mice using various type adjuvant. The novel type-inactivated vaccine candidate was constructed by adding Chlorhexidine digluconate solution. BALB/c mice were divided into 6 groups of 15 mice apiece. The mice were intramuscularly (IM) primed at 6 weeks of age and were IM boosted 8 weeks of age. Groups A and B mice were injected with sterile phosphate-buffered saline as controls; group C mice were inoculated with 5×10⁸ cells/100 µL of formalin-inactivated S. Typhimurium cells and adjuvant ISA70; groups D~F mice were immunized with 5×10⁸ cells/100 µL of the inactivated vaccine candidate and adjuvant ISA70, adjuvant IMS1313 and adjuvant IMS1313 containing 30 ㎍/mL of GI24, respectively. All mice (except group A mice) were orally challenged with a virulent S. Typhimurium strain at 10 weeks of age. Mice from groups C-F had significantly increased IgG levels compared to control groups (A-B) mice. The levels of splenocyte IFN-γ and IL-4 in mice of all groups were measured by ELISA, resulting in increased immunity in group F mice compared to those of groups A-E mice. These data suggested that systemic and cell-mediated immune responses were highly induced by IM immunization with the vaccine candidate and adjuvant IMS1313 containing GI24. Furthermore, clinical signs such as death were observed in only 20% of group F mice after virulent Salmonella strain challenge, however, groups B and C (100%), and groups D and E (60%) mice died. This data suggested that mice immunized by intramuscular prime and booster with this vaccine candidate and adjuvant IMS1313 containing GI24 effectively protected mice from salmonellosis.

• Parasites, Hosts and Diseases
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• v.51 no.2
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• pp.155-163
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• 2013

This study aimed to evaluate the efficacy of fructose-1,6-bis phosphate aldolase (SMALDO) DNA vaccination against Schistosoma mansoni infection using different routes of injection. The SMALDO has been cloned into the eukaryotic expression vector pcDNA3.1/V5-His TOPO-TA and was used in injecting Swiss albino mice intramuscularly (IM), subcutaneously (SC), or intraperitoneally (IP) ($50{\mu}g/mouse$). Mice vaccinated with non-recombinant pcDNA3.1 served as controls. Each group was immunized 4 times at weeks 0, 2, 4, and 6. Two weeks after the last booster dose, all mice groups were infected with 80 S. mansoni cercariae via tail immersion. At week 8 post-infection, animals were sacrificed for assessment of parasitological and histopathological parameters. High anti-SMALDO IgG antibody titers were detected in sera of all vaccinated groups (P<0.01) compared to the control group. Both the IP and SC vaccination routes resulted in a significant reduction in worm burden (46.2% and 28.9%, respectively, P<0.01). This was accompanied by a significant reduction in hepatic and intestinal egg counts (41.7% and 40.2%, respectively, P<0.01) in the IP group only. The number of dead eggs was significantly increased in both IP and IM groups (P<0.01). IP vaccination recorded the highest significant reduction in granuloma number and diameter (54.7% and 29.2%, respectively, P<0.01) and significant increase in dead miracidia (P<0.01). In conclusion, changing the injection route of SMALDO DNA vaccination significantly influenced the efficacy of vaccination. SMALDO DNA vaccination via IP route could be a promising protective and antipathology vaccine candidate against S. mansoni infection.

• Journal of Microbiology and Biotechnology
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• v.33 no.2
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• pp.167-179
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• 2023

The rifampicin-resistant strain E9-302 of Edwardsiella ictaluri strain 669 (WT) was generated by continuous passage on BHI agar plates containing increasing concentrations of rifampicin. E9-302 was attenuated significantly by 119 times to zebrafish Danio rerio compared to WT in terms of the 50% lethal dose (LD₅₀). Zebrafish vaccinated with E9-302 via intraperitoneal (IP) injection at a dose of 1 × 10³ CFU/fish had relative percentage survival (RPS) rates of 85.7% when challenged with wild-type E. ictaluri via IP 14 days post-vaccination (dpv). After 14 days of primary vaccination with E9-302 via immersion (IM) at a dose of 4 × 10⁷ CFU/ml, a booster IM vaccination with E9-302 at a dose of 2 × 10⁷ CFU/ml exhibited 65.2% RPS against challenge with wild-type E. ictaluri via IP 7 days later. These results indicated that the rifampicin-resistant attenuated strain E9-302 had potential as a live vaccine against E. ictaluri infection. A previously unreported amino acid site change at position 142 of the RNA polymerase (RNAP) β subunit encoded by the gene rpoB associated with rifampicin resistance was identified. Analysis of the whole-genome sequencing results revealed multiple missense mutations in the virulence-related genes esrB and sspH2 in E9-302 compared with WT, and a 189 bp mismatch in one gene, whose coding product was highly homologous to glycosyltransferase family 39 protein. This study preliminarily explored the molecular mechanism underlying the virulence attenuation of rifampicin-resistant strain E9-302 and provided a new target for the subsequent study of the pathogenic mechanism of E. ictaluri.

• The Journal of Korean Society of Virology
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• v.29 no.2
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• pp.55-64
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• 1999

In Yugoslavia, hemorrhagic fever with renal syndrome (HFRS) is one of the important national health problem, but no vaccine has been used to prevent HFRS. Since first HFRS case in 1952, sporadic cases of HFRS occurred every year and over 4,000 registered cases with $1{\sim}16%$ mortality so far. We performed a prospective, randomized double-blind placebo-controlled trial to evaluate the effectiveness of $Hantavax^{TM}$ against HFRS in 3,900 healthy adults living in the endemic areas of Yugoslavia. 1,900 people were given 0.5 ml of Hantavax subcutaneously twice at one month interval and a booster shot at one year after. For controls other 2,000 healthy people were given 0.5 ml of physiolosical saline as a placebo. We investigated HFRS cases in both the vaccinated and nonvaccinated groups by monitoring the program for patient registration in the areas from 1996 to 1998, and the effect of vaccine was analyzed epidemiologically. No confirmed case of HFRS was observed among 1,900 Hantavax vaccinees, while 20 confirmed cases were observed among 2,000 nonvaccinated control group. There were no remarkable side effects among the vaccinees either locally or in general after inoculation of the vaccine. The Hantavax vaccine showed statistically significant protective efficacy against HFRS among Yugoslavian people.

• The Journal of Korean Society of Virology
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• v.27 no.1
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• pp.39-47
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• 1997

A large number of viruses belonging to Genus Hantavirus in Family Bunyaviridae are etiologic agents for hemorrhagic fever with renal syndrome (HFRS), or hantavirus pulmonary syndrome (HPS). Hantaan (HTN), Seoul (SED), Belgrade (BEL), Puumala (PUU) serotype viruses are well known causative agents for HFRS in Eurasian continent. Among those viruses Hantaan and Seoul serotypes are well known to cause HFRS in Korea, but there are some sporadic incidence by other than Hantaan or Seoul viruses. Recently we have developed the combined Hantaan-Puumala virus vaccine to prevent world-wide occuring HFRS. This combined vaccine is formalin inactivated, suckling mouse and suckling hamster brain extracts for Hantaan and Puumala viruses, respectively. Protein contents of this purified candidate vaccine is $27\;{\mu}g/ml$, which contains 1,024 ELISA antigen units to each virus, but content of myelin basic protein which is causing experimental allergic encephalomyelitis is less than 0.1 ng/ml. Thirty hamsters were given twice at one month interval intra-muscularly and bled on 30 days after each vaccination from retro-orbital sinus vein. Antibody titers were tested against 5 major serotype viruses, Hantaan, Seoul, Belgrade, Puumala and Sin Nombre viruses by IFA and PRNT. The mean IF antibody titers on 30 days after primary shot were 78.4, 68.8, 68.8, 37.9, and 15.6; mean neutralizing antibody titers were 65.4, 12, 6.1, 65.6 and 0.5 against Hantaan, Seoul, Belgrade, Puumala and Sin Nombre viruses, respectively. The mean IF antibody titers on 30 days after booster shot were 686.9, 567.5, 550.4, 516.3, and 430.9; and neutralizing antibody titers were 710.8, 41.9, 24.3, 409.9, and 1.6 against Hantaan, Seoul, Belgrade, Puumala and Sin Nombre viruses, respectively.

• Food Science and Biotechnology
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• v.27 no.6
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• pp.1823-1831
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• 2018

This study examined the efficacy of Atractylodes macrocephala Koidz (AMK) protein and polysaccharide extracts as adjuvant or adjuvant booster when given together with porcine pleuropneumonia vaccine. Experimental mice (n = 5/group) were subcutaneously immunized with $25{\mu}g$ ApxIIA #3 antigen, a target protein against A. pleuropneumoniae, together with alum and/or various concentrations ($0-500{\mu}g$) of the AMK extracts, while the control group received PBS only. Immunization with ApxIIA #3 antigen increased the antigen-specific IgG titer and this increase was enhanced in the immunization together with AMK protein, but not polysaccharide extract. Supplementation of AMK protein extract exhibited dose-dependent increases in the antigen-induced protective immunity against A. pleuropneumoniae challenge and in the lymphocyte proliferation specific to the antigen. Glycoproteins present in the AMK extract were the active components responsible for immune response induction. Collectively, the present findings suggest that AMK glycoproteins are useful as immune stimulating adjuvant or adjuvant booster.