• Molecules and Cells
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• 제46권1호
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• pp.41-47
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• 2023

The rapid development of mRNA vaccines has contributed to the management of the current coronavirus disease 2019 (COVID-19) pandemic, suggesting that this technology may be used to manage future outbreaks of infectious diseases. Because the antigens targeted by mRNA vaccines can be easily altered by simply changing the sequence present in the coding region of mRNA structures, it is more appropriate to develop vaccines, especially during rapidly developing outbreaks of infectious diseases. In addition to allowing rapid development, mRNA vaccines have great potential in inducing successful antigen-specific immunity by expressing target antigens in cells and simultaneously triggering immune responses. Indeed, the two COVID-19 mRNA vaccines approved by the U.S. Food and Drug Administration have shown significant efficacy in preventing infections. The ability of mRNAs to produce target proteins that are defective in specific diseases has enabled the development of options to treat intractable diseases. Clinical applications of mRNA vaccines/therapeutics require strategies to safely deliver the RNA molecules into targeted cells. The present review summarizes current knowledge about mRNA vaccines/ therapeutics, their clinical applications, and their delivery strategies.

• 한국가금학회지
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• 제26권3호
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• pp.149-170
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• 1999

Protozoa of the genus Eimeria are the etiologic agents of avian coccidiosis, the most economically important Parasitic disease for the poultry industry. Coccidia multiply in intestinal epithelial cells of a wide range of hosts, including livestock in addition to poultry. Chemotherapy is extensively used to control coccidiosis. However, development of drug resistance by Eimeria parasites, the intensive cost and labor involved in the identification of new anticoccidial compounds and public awareness of drug residues in foods warrant alternative methods to prevent coccidiocic in the fast growing poultry industry. For these reasons, there is a great interest in developing vaccines against avian coccidiosis. Live Eimeria vaccines confer protective immunity, however a significant disadvantage of using these types of vaccines is their pathogenicity. Live parasites with attenuated pathogenicity also usually produce immunity but may revert back to a pathogenic form and may be contaminated with other pathogenic organisms. Killed Eimeria vaccines are safer but, unlike live attenuated vaccines, are not able to generate cytotoxic T lymphocyte responses. Recombinant vaccines are biochemically purified proteins produced by genetic engineering that consist of particular epitopes or metabolites of Eimeria. Unlike live attenuated organisms, recombinant vaccines do not possess as much risk and generally are able to induce both humoral and cell mediated immunity. DNA vaccines consist of genes encoding immunogenic proteins of pathogens that are directly administered into the host in a manner that the gene is expressed and the resulting protein generates a protective immune response. Although all of these different types of vaccines have been applied to coccidiosis, this disease continues to cause substantial morbidity and mortality in the poultry industry. Future development of an effective vaccine against coccidiosis will depend on further investigation of protective immunity to Eimeria infection and identification of important immundgenic parasite molecules.

• 대한수의학회지
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• 제42권2호
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• pp.241-251
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• 2002

Modified-live (ML) infectious laryngotracheitis (ILT) vaccines have been widely used as a preventive measure in Korea since the first outbreak of ITL. Recently, it has been observed that chickens vaccinated with the commercially available ML ILT vaccine have sometimes exhibited adverse clinical signs. In this study, we evaluated the quality of the vaccines by comparing titer of each vaccine batch and testing the stability of ILT virus (ILTV) in vaccine diluents and compared the safety and efficacy of vaccines in specific pathogen free (SPF) chickens. The ratio of maximum titer to minimum titer of vaccine produced by most manufacturers was 2 to 15. However, 2 out of 11 manufacturers produced vaccines of which the ratio was 74 to 478. Most vaccines examined were maintained vaccine titers suitable for national regulations within expiry date. However, some vaccines did not keep the titer required for the national regulations. In the test for stability of ILTV in various diluents, ILTV was highly stable in lactose-phosphate-glutamine-gelatin solution, sucrose-phophate-glutamine-albumin solution and some vaccine diluents produced by manufacturers. The safety of ML ILT vaccines was assessed in 10-day-old SPF chicks. Mortality in SPF chicks inoculated intratracheally with one dose of vaccine varied depending on vaccines and some vaccines produced 50-85% mortality. Seven-week-old SPF chickens were vaccinated intraocularly with ML ILT vaccines and then challenged intratracheally with ILT challenge virus 14 days after vaccination. The protection rate was assessed by clinical signs and reisolation of the ILT challenge virus from tracheas taken at day 4 after challenge. There were slight respiratory reactions in some vaccinated chickens after vaccination but these reactions disappeared within 5 days after vaccination. No further clinical signs and death were observed. Protection rate determined by clinical signs and mortality was 100% in all vaccinated groups. However, the challenge virus was isolated from all tracheas of chickens vaccinated with vaccine B or control groups. The challenge virus was also isolated in the trachea of one in five chickens vaccinated with either vaccine F or K, but not in tracheas of chickens vaccinated with other vaccines. In the present study, the stability of vaccine diluents, pathogenicity and protection rate based on reisolation test of the challenge virus were different depending on vaccines produced by eleven manufacturers.

• Biomolecules & Therapeutics
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• 제25권4호
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• pp.345-353
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• 2017

Plant expression systems have been developed to produce anti-cancer vaccines. Plants have several advantages as bioreactors for the production of subunit vaccines: they are considered safe, and may be used to produce recombinant proteins at low production cost. However, several technical issues hinder large-scale production of anti-cancer vaccines in plants. The present review covers design strategies to enhance the immunogenicity and therapeutic potency of anti-cancer vaccines, methods to increase vaccine-expressing plant biomass, and challenges facing the production of anti-cancer vaccines in plants. Specifically, the issues such as low expression levels and plant-specific glycosylation are described, along with their potential solutions.

• Pediatric Infection and Vaccine
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• 제16권1호
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• pp.24-30
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• 2009

The vaccines has been developed over the first two hundred years since Jenner's smallpox vaccination. In modern days, vaccination has had the largest impact on the incidence and persistence of infections. Although natural infection induces lifelong immunity, the assumption that the vaccine also confers permanent protection has been reconsidered following outbreaks of measles in students who had been vaccinated 15-20 years prior to infection in the US in the 1980s. Clinical studies have proposed several mechanisms such as vaccine failure in some individuals and the subsequent loss of immunity after vaccination. An ideal vaccine is relatively easy to define, but few real vaccines approach the ideal. Many difficulties account for the failure in producing these ideal vaccines. However, recent advances in methods for studying immune response to pathogens have provided a better understanding of immune mechanisms. Based on these findings, the development of good vaccine formulations allowing stimulation of optimal and prolonged protective immunity and immunization policies or schedules should lead to the introduction of vaccines for previously resistant organisms.

• Journal of Ginseng Research
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• 제47권2호
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• pp.347-348
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• 2023

Vaccines help protect people from infections. However, Coronavirus 2019 (COVID-19) vaccinees often still become infected with COVID-19 variants (breakthrough infections) and may go on to suffer from long COVID symptoms due to short-lasting immunity and less-effective protection provided by available vaccines. Moreover, the current COVID-19 vaccines do not prevent viral transmission and ward off only about 15% of breakthrough infections. To prepare more effective vaccines, it is essential to predict the viral strains that will be circulating based on available epidemiological data. The World Health Organization recommends in advance which influenza strains are expected to be prevalent during influenza season to guide the production of influenza vaccines by pharmaceutical companies. However, future emerging COVID-19 strain(s) have not been possible to predict since no sound epidemiological information has been established. Thus, for more effective protection, immune stimulators alone or in combination with vaccines would be preferable to protect people from COVID-19 infection. One of those remedies would be ginseng, which has been used for potentiating immunity in the past.

• Osong Public Health and Research Perspectives
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• 제8권6호
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• pp.389-396
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• 2017

Objectives: To circumvent the limitations of the current golden standard method, colony-forming unit (CFU) assay, for viability of Bacille Calmette-$Gu{\acute{e}}rin$ (BCG) vaccines, we developed a new method to rapidly and accurately determine the potency of BCG vaccines. Methods: Based on flow cytometry (FACS) and fluorescein diacetate (FDA) as the most appropriate fluorescent staining reagent, 17 lots of BCG vaccines for percutaneous administration and 5 lots of BCG vaccines for intradermal administration were analyzed in this study. The percentage of viable cells measured by flow cytometry along with the total number of organisms in BCG vaccines, as determined on a cell counter, was used to quantify the number of viable cells. Results: Pearson correlation coefficients of FACS and CFU assays for percutaneous and intradermal BCG vaccines were 0.6962 and 0.7428, respectively, indicating a high correlation. The coefficient of variation value of the FACS assay was less than 7%, which was 11 times lower than that of the CFU assay. Conclusion: This study contributes to the evaluation of new potency test method for FACS-based determination of viable cells in BCG vaccines. Accordingly, quality control of BCG vaccines can be significantly improved.

• IMMUNE NETWORK
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• 제5권2호
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• pp.55-67
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• 2005

Cancer vaccine is an active immunotherapy to stimulate the immune system to mount a response against the tumor specific antigen. Working as a stimulant to the body's own immune system, cancer vaccines help the body recognize and destroy targeted cancers and may help to shrink advanced tumors. Research is currently underway to develop therapeutic cancer vaccines. It is also possible to develop prophylactic vaccines in the future. The whole cell approach to eradicate cancer has used whole cancer cells to make vaccine. In an early stage of this approach, whole cell lysate or a mixture of immunoadjuvant and inactivated cancer cells has been used. Improved vaccines are being developed that utilize cytokines or costimulatory molecules to mount an attack against cancer cells. In case of melanoma, these vaccines are expected to have a therapeutic effect of vaccine. Furthermore, it is attempting to treat stomach cancer, colorectal cancer, pancreatic cancer, and prostate cancer. Other vaccines are being developing that are peptide vaccine, recombinant vaccine and dendritic cell vaccine. Out of them, reintroduction of antigen-specific dendritic cells into patient and DNA vaccine are mostly being conducted. Currently, research and development efforts are underway to develop therapeutic cancer vaccine such as DNA vaccine for the treatment of multiple forms of cancers.

• Molecules and Cells
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• 제27권1호
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• pp.5-14
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• 2009

The availability of effective vaccines has had the most profound positive effect on improving the quality of public health by preventing infectious diseases. Despite many successful vaccines, there are still old and new emerging pathogens against which there is no vaccine available. A better understanding of how vaccines work for providing protection will help to improve current vaccines as well as to develop effective vaccines against pathogens for which we do not have a proper means to control. Recent studies have focused on innate immunity as the first line of host defense and its role in inducing adaptive immunity; such studies have been an intense area of research, which will reveal the immunological mechanisms how vaccines work for protection. Toll-like receptors (TLRs), a family of receptors for pathogen-associated molecular patterns on cells of the innate immune system, play a critical role in detecting and responding to microbial infections. Importantly, the innate immune system modulates the quantity and quality of long-term T and B cell memory and protective immune responses to pathogens. Limited studies suggest that vaccines which mimic natural infection and/or the structure of pathogens seem to be effective in inducing long-term protective immunity. A better understanding of the similarities and differences of the molecular and cellular events in host responses to vaccination and pathogen infection would enable the rationale for design of novel preventive measures against many challenging pathogens.

• 한국동물위생학회지
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• 제36권1호
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• pp.1-6
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• 2013

Since the 1980's, several kinds of inactivated bovine viral diarrhea virus (BVDV) vaccines have been used to immunize domestic animals such as cattle and goat in Korea. Immunogenicity of the BVDV vaccines has been checked by the Korean Veterinary Authority using laboratory animals. In this study, we applied a molecular method to investigate the genetic characterization of the BVDV genes in six commercial inactivated BVDV vaccines, and determined the efficiency of two extraction reagents (i.e., sodium citrate or isopropyl myristate) to separate the vaccine antigens from the antigen/adjuvant complexes. Six partial non-coding regions (288 bp) were successfully amplified with specific primer sets, which demonstrated that sodium citrate is more efficient in extracting viral RNA from inactivated gel vaccines than isopropyl myristae. In addition, we identified the virus strains from the vaccines by analyzing the nucleotide sequences of the 5' non-coding region (NCR) of BVDV. The nucleotide similarity of the partial 5' NCR ranged from 95.1 to 100% among BVDV vaccine strains, respectively, indicating that a few manufacturers used different BVDV strains to produce their vaccines.