• Journal of Plant Biotechnology
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• v.37 no.3
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• pp.269-274
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• 2010

As the capture fishing industry has declined, the aquaculture industry has become an important source of seafood. With this tendency all fish farming will be performed by large-scale farms where the fish are cultivated in much high density and as a result the incidence of infectious diseases increases. Therefore, vaccination has become an increasingly important part of aquaculture as a cost effective method of controlling various diseases. The early fish vaccines were the formalin inactivated bacteria or virus cultures, which were administered by either immersion or injection. Recombinant DNA biotechnology allowed us to develop orally administrated DNA and recombinant vaccines. In terms of the manufacturing process and cost, Lemna and Spirodela is the most efficient and reliable plant expression system for the production of edible vaccine.

• Pediatric Infection and Vaccine
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• v.15 no.2
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• pp.108-114
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• 2008

Japanese encephalitis is the leading cause of viral encephalitis in Asia, where it accounts for up to 50,000 cases. Approximately 20% of affected patients die, and 30-50% of survivors have significant neurological sequelae. Inactivated mouse-brain derived Japanese encephalitis vaccines has been effectively implemented to control the disease effectively in Korea and several other Asian countries. However, the vaccine is expensive and difficult to produce, requires multiple doses, and has been associated with hypersensitivity reactions and rare adverse neurologicale events. The live-attenuated SA14-14-2 vaccine derived from primary hamster kidney (PHK) cells was developed in China and has been used there since 1988. Outside China, it has been licensed and used in Korea and several other Asian countries. This vaccine is effective and inexpensive. However, the lack of precedence for using a PHK cell substrate in a live-attenuated vaccine is a special issue of concern. The WHO working group has recommended additional safety studies in selected high-risk groups, as well as ongoing post-marketing studies to ensure long-term safety. Recently, a new inactivated vaccine and live-attenuated chimeric vaccine have been developed from vero cells. With this background, this article summarized the current status of Japanese encephalitis vaccination worldwide and in Korea.

• The Journal of the Korean Society for Microbiology
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• v.8 no.1
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• pp.37-42
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• 1973

For the preparation of non-infective vaccine against typhoid fever, the authors had carried out an investigation on the possibilities of using $^{60}Co\;{\gamma}$-ray irradiation for the inactivation of Salmonella typhi Ty 2. The following results were obtained. 1) Chicks shortly after hatching were higher susceptible than mice to intracerebral injection with S. typhi. 2) In safety test on experimental animal, $^{60}Co\;{\gamma}$-ray irradiated vaccines demonstrated no clinical symptom while the phenol treated vaccines revealed several cases of narcosis by intraperitoneal injection in chicks. 3) The rabbit antisera immunized with $^{60}Co\;{\gamma}$-ray irradiated and phenol treated vaccine revealed almost same agglutinin titers to each other. 4) In potency test in chicks, there was no significance in the protective capacity between $^{60}Co\;{\gamma}$-ray irradiated and phenol treated vaccines.

• Journal of fish pathology
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• v.34 no.2
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• pp.177-184
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• 2021

Vaccines based on single-cycle viruses that are replication-incompetent due to knockout of replication-related structural gene(s) are more immunogenic than inactivated or subunit vaccines and can be used as delivery vehicles for foreign antigens without concerns on the reverting to virulent forms. The aim of this study was to develop a delivery vehicle for nervous necrosis virus (NNV)-like particles (VLPs) using G gene deleted single-cycle VHSV (rVHSV-𝚫G). Recombinant single-cycle VHSVs carrying NNV capsid protein gene between N and P gene of rVHSV-𝚫G genome (rVHSV-𝚫G-NNV_Cap) were rescued by reverse genetic technology. The successful expression of NNV capsid protein in cells infected with rVHSV-𝚫G-NNV_Cap was demonstrated by Western blot analysis, and the production of NNV VLPs in infected cells was confirmed using an electron microscopy. The results suggest that single-cycle VHSVs can be used as a safe delivery vehicle for NNV VLPs, and can be extended to other pathogens for the development of prophylactic vaccines.

• 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 Life Science
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• v.33 no.9
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• pp.746-753
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• 2023

Viral infectious diseases have been regarded as one of the greatest threats to global public health. The recent coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a stark reminder of the threat posed by emerging viral infections. Developing and producing appropriate and efficient vaccines and therapeutics are the only options to combat this pandemic. The COVID-19 pandemic has highlighted the need for novel vaccine platforms to control and prevent emerging viral diseases. Conventional vaccine platforms, including live-attenuated vaccine and inactivated vaccines, pose limitations in the speed of vaccine development, manufacturing capacity, and broad protection for emergency use. Interestingly, vaccination with the SARS-CoV-2 vaccine candidate based on the mRNA-lipid nanoparticle (LNP) platform protected against COVID-19, confirming that the nucleoside-modified candidate is a safe and effective alternative to conventional vaccines. Moreover, the prophylactic strategies against the COVID-19 pandemic have been mRNA nucleic acid-based vaccines and nanoparticle-based platforms, which are effective against SARS-CoV-2 and its variants. Overall, the novel vaccine platform has presented advantages compared with the traditional vaccine platform in the COVID-19 pandemic. This review explores the recent advancements in vaccine technologies and platforms, focusing on mRNA vaccines, digital vaccines, and nanoparticles while considering their advantages and possible drawbacks.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.6
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• pp.644-649
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• 2019

Killed vaccines, developed by inactivation with formalin, have been investigated for many fish viruses. In this study, the inactivation of viral hemorrhagic septicemia virus (VHSV) by formalin was investigated based on the infectivity titer. When viral cell culture supernatants were used, the infectivity titer decreased 1,000-fold at 1 d after treatment with 0.1% (v/v) formalin, but was below the detection limit at 7 and 14 d. Moreover, neither the N nor G gene were detectable by RT-PCR immediately after formalin treatment. In western blot analysis, N protein was not detected by rabbit antiserum against VHSV KR-9225 from 2 d after formalin treatment. On the other hand, when we used a virus that was purified and concentrated ~100 times, the infectivity titer was maintained at 10^6.05 TCID₅₀/mL, even at 14 d after formalin treatment, and no change in the viral structural proteins was observed. This study provides important data on the production and use of formalin-inactivated vaccines.

• Clinical and Experimental Pediatrics
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• v.62 no.7
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• pp.252-256
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• 2019

The Committee on Infectious Diseases of the Korean Pediatric Society recommended immunization schedule for children and adolescents aged 18 years or younger in the 9th (2018) edition of Immunization guideline. This report provides the revised recommendations made by the committee and summarizes several changes from the 2015 guideline. National immunization program (NIP) launched a human papillomavirus (HPV) immunization for girls aged 12 years in 2016. NIP has also expanded age indication for inactivated influenza vaccine (IIV) to 12 years of age in the 2018-2019 season. Quadrivalent IIVs with a full dose (0.5 mL) are approved for all children of 6 months or older. Recommendations of live attenuated influenza vaccine were removed. For inactivated Japanese encephalitis vaccine, first 2 doses are considered as the primary series. Recommendations for use of newly introduced vaccines (diphtheria-tetanus-acellular pertussis/inactivated poliovirus/Haemophilus influenzae type b, 9-valent HPV, new varicella vaccine, new quadrivalent IIV, and attenuated oral typhoid vaccine) were added. Lastly, monitoring system for adverse events following immunization was updated. Other changes can be found in the 9th edition of Immunization guideline in detail.

• Korean Journal of Veterinary Service
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• v.46 no.4
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• pp.263-268
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• 2023

Despite regular vaccinations, equine influenza virus (EIV) and Streptococcus equi subsp. equi (strangles) are the cause of highly contagious respiratory infections in horses. Many recent studies have reported that the concurrent administration of two vaccines could simplify horse management and minimize veterinary expenses. However, there is little information available regarding the efficacy of concurrent vaccinations against EIV and strangles. In this study, we evaluated EIV-specific antibody responses following the single EIV vaccination with the recombinant viral-vectored EIV vaccine or concurrent vaccination with the EIV and inactivated strangles vaccines. Blood samples were collected at 1-, 2-, 4-, and 8 weeks post-immunization (wpi) from each group. EIV-specific antibodies were evaluated by enzyme-linked immunosorbent assay (ELISA) and hemagglutination inhibition (HAI) assay. Both single and concurrent vaccination showed similar levels of EIV-specific serum immunoglobulin g (IgG) at 1 and 2 wpi. However, at 4 to 8 wpi, the EIV-only vaccination group showed significantly higher serum IgG levels than those from the concurrently vaccinated group. The HAI titers showed similar trends as the ELISA data, except at 8 wpi when both groups presented HAI titers with no significant differences. These data demonstrate that the concurrent vaccination against EIV and strangles could compromise the humoral immune response to equine influenza between vaccination intervals, which suggests the use of the consecutive vaccination protocol for EIV and strangles rather than concurrent vaccination.

• Journal of Life Science
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• v.32 no.12
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• pp.919-928
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• 2022

As seen in the COVID-19 pandemic, unexpected emergence of new viruses presents serious concern on public health. Especially, the absence of effective vaccines or antiviral drugs against emerging viruses significantly increases the severity of disease and duration of viral circulation among population. Natural products have served as a major source for safe and effective antiviral drugs. In this study, we examined the virucidal activity of medical herb extracts with a view to discover novel antiviral agents with desired levels of safety and antiviral efficacy. Ethanol extracts of ten selected medical herbs were tested for antioxidant activity and in-vitro cytotoxicity in various animal cell lines. Of note, the herbal extracts showed broad and potent virucidal activities against rotavirus, hepatitis A virus, and influenza A virus. The extracts of Sorbus commixta and Glycyrrhiza uralensis showed strong virucidal activities against influenza A virus. We also examined whether the extracts of Sorbus commixta and Glycyrrhiza uralensis can be used as inactivating agents to prepare an inactivated viral vaccine. In a mouse model, influenza A virus inactivated by the extracts elicited high levels of neutralizing antibodies, and the vaccination provided complete protection against lethal challenge. These results suggest that herb-derived natural products can be developed to antiviral drugs as well as inactivating agents for preparation of inactivated viral vaccines.