• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.11a
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• pp.115-120
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• 1996

Vaccination has been considered to be the most effective way to control infectious diseases. Currently, many vaccines used in humans are live-attenuated or killed microorganisms. Polio, mumps, and measles vaccines are live-attenuated. Killed vaccines include cholera and pertussis vaccines, These conventional vaccines, however, suffer from some problems. In the case of live-attenuated vaccines, reversion to virulence is observed in a small but significant number of clinical cases each year. In killed vaccines, due to the possible hazard to employees working with live pathogens, the cost of preparation is high. Killed vaccines also need to be given in multiple doses, Furthermore, both live-attenuated and killed vaccines have possible presence of cellular materials leading to side effects. Moreover, there are diseases such as malaria and hepatitis for which conventional attenuated and killed vaccines are not available because the pathogens cannot be grown in sufficient amounts to allow the classical methods to be used.

• Korean Journal of Poultry Science
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• v.26 no.3
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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.

• Korean Journal of Veterinary Service
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• v.46 no.3
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• pp.193-202
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• 2023

Porcine epidemic diarrhea is an infectious intestinal disease caused by the porcine epidemic diarrhea virus (PEDV). Especially, when suckling piglets are infected, the mortality rate is close to 100%. PEDV is classified into G1 and G2 types based on genetic differences. The G2 type PEDV outbreak in the United States in 2013 was highly pathogenic and contagious, and it has spread worldwide and caused continuous economic losses. Most commercial vaccines used are G1 type vaccines, and existing vaccines do not fully protect piglets due to genetic differences. In this study, we evaluated the safety of the newly developed G2 type attenuated HSGP vaccine strain by inoculating it into piglets and testing whether the vaccine virus spreads to the non-vaccinated, negative pigs and whether the vaccine reverts to its virulence during serial passage experiments. Each experiment lasted for 7 days for each passage, and fecal viral titers, clinical symptoms, and weight gain were measured daily. After the experiment, necropsy was performed to measure intestinal virus titer and pathological evaluation. As a result of the first passage, no transmission of the vaccine virus to negative pigs co-housed with vaccinated pigs was observed. In addition, after four consecutive passage experiments, the clinical symptoms and small intestine lesions were gradually alleviated, and no virus was detected in the feces in the fourth passage experiment. Therefore, it was concluded that the vaccine was safe without virulence reversion in accordance with the guidelines of the current licensing authority. However, further studies are needed on the genetic changes and biological characteristics of the mutant virus that occur during successive passages of the attenuated vaccine since the replication and clinical symptoms of the virus increased until the third passage during successive passages of the vaccine virus. Based on this study, it was concluded that virulence reversion and safety evaluation of attenuated vaccines through serial passage in target animals can be useful to evaluate the safety of attenuated viruses.

• KSBB Journal
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• v.25 no.6
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• pp.497-506
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• 2010

Vaccine is a protective clinical measure capable of persuading immune system against infectious agents. Vaccine can be categorized as live attenuated and inactivated. Live attenuated vaccines activate immunity similar to natural infection by replicating living organisms whereas inactivated vaccines are either whole cell vaccines, eliciting immune response by killed organisms,or subunit vaccines, stimulating immunity by non-replicating sub cellular parts. The components of vaccine play a critical role in deciding the immune response mediated by the vaccine. The innate immune responds against the antigen component. Adjuvants represent an importantcomponent of vaccine for enhancing the immunogenicity of the antigens. Subunit vaccines with isolated fractions of killed and recombinant antigens are mostly co-administered with adjuvants. The delivery system of the vaccine is another essential component to ensurethat vaccine is delivered to the right target with right dosage form. Furthermore, vaccine delivery system ensures that the desired immune response is achieved by manipulating the optimal interaction of vaccine and adjuvantwith the immune cell. The aforementioned components along with routes of administration of vaccine are the key elements of a successful vaccination procedure. Vaccines can be administered either orally or by parenteral routes. Many groups had made remarkable efforts for the development of new vaccine and delivery system. The emergence of new vaccine delivery system may lead to pursue the immunization goals with better clinical practices.

• Pediatric Infection and Vaccine
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• v.16 no.2
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• pp.183-190
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• 2009

Purpose : To evaluate the number and severity of adverse reactions after Japanese Encephalitis (JE) vaccination in children using different vaccines (inactivated vaccine or live attenuated vaccine) and to determine the ability and safety of the vaccines to provide effective immunization for JE. Methods : From August 2006 to February 2007, we conducted a prospective cohort study of the adverse reactions associated with JE immunization in Korea. We investigated common adverse reactions during the 4 days following immunization using telephone collaborations with four public health centers and nine pediatric clinics. Results : The mean age of children receiving the inactivated vaccines and live attenuated vaccines, respectively, were 1.4 y (range: 1 to 8.5) and 1.7 y (range: 1 to 8.3). The number of children that received the inactivated vaccines was 425 (64.6%). A total of 233 (35.4%) received the live attenuated vaccines. Fourteen children (3.3%) had more than one localized adverse event with the inactivated vaccine, and six (2.6%) had more than one event with the live attenuated vaccine (P =0.607). Systemic adverse reactions occurred in 5.2% vs. 8.2%, respectively, of these groups (P =0.131). Fever was more common in the live attenuated vaccine group than in the inactivated vaccine group on the day of vaccination (P =0.026). Conclusions : The rate of adverse events in our study was even lower than that previously reported. No significant difference in outcomes between inactivated vaccine and live attenuated vaccine was found in JE-immunized children. Fever was more common in the live attenuated vaccine group than in the inactivated vaccine group on the day of vaccination.

• IMMUNE NETWORK
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• v.2 no.1
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• pp.1-5
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• 2002

Estimated number of adults and children newly infected with HIV-1 during 2001 alone is 5 million in total. An effective vaccine, in addition to education & public health approaches, has been believed to be the best option to stop the HIV-1 transmission, especially for developing countries. Among AIDS vaccine candidates, DNA vaccine is relatively safe and, in a certain extent, mimics some attributes of live attenuated vaccine, with regard to in vivo gene expression & the type of immunity induced. We recently demonstrated that DNA vaccines expressing SIVmac239 structural and regulatory genes, augmented with coadministration of IL-12 mutant induced the strongest T cell responses, resulting in low to undetectable setpoint viral loads, stable $CD4^+$ T cell counts, and no evidence of clinical diseases or mortality by day 420 after challenge. This finding is the second demonstration, following the protective result of live attenuated SIV vaccine in SIVmac-rhesus monkey model, which was known to have safety problem. So, our DNA vaccines could give a significant impact on HIV-1 epidemic by slowing or stopping the spread of HIV-1, leading to eventual eradication of HIV-1 and AIDS in the population.

• The Korean Journal of Pain
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• v.33 no.3
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• pp.201-207
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• 2020

Postherpetic neuralgia (PHN) is a challenging condition for pain management specialists. The prevention of herpes zoster (HZ) and subsequent PHN in individuals aged 50 years and older, via the development of new vaccines, is an ongoing research project. The live zoster vaccine (LZV, Zostavax^®) was the first proof of concept that vaccination could prevent HZ, but LZV cannot be used in various immunecompromised patients. This led to the development of a new non-live recombinant zoster vaccine (RZV, Shingrix^®). This RZV has shown promising results in many clinical trials, with high reactogenicity and similar systemic adverse effects compared to those of LZV. The National Advisory Committee on Immunization has recommended LZV as a standard vaccine for HZ prevention in adults ≥ 50 years of age, but no studies directly comparing the safety and efficacy of RZV and LZV vaccines have been conducted. This article reviews the brief history, efficacy, and safety of the two vaccines and discusses the advantage of RZV over LZV based on the available literature.

• Proceedings of the Korean Society of Life Science Conference
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• 2007.10a
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• pp.47.1-47.1
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• 2007

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• Korean Journal of Veterinary Research
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• v.49 no.3
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• pp.201-205
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• 2009

In this study, we evaluated the stability and potency of live attenuated rinderpest vaccines of lapinized-avianized tissue culture strain origin, which had been produced annually from 2005 to 2008. When immune responses to the vaccines were evaluated using two Holstein calves weighing 100~150 kg, neutralizing antibody titer of 1 : 16 was induced at 21 days post vaccination. When calves were also inoculated with vaccines lots that had been stored for 39 months at ${4^{\circ}C}$, same level of antibody titer was observed. Using the virus titer test, we found that all batches of the vaccine that had been kept for 3, 10, 15, 22, 27, 34, 39, and 45 months showed no significant loss of titers, and fulfilled the requirement necessary ($\geq$ 3 $logTCID_50$) to be used as the national rinderpest vaccine reserve in Korea. In this study, we demonstrated that stability and potency of the rinderpest vaccines were maintained over three years when kept at ${4^{\circ}C}$ storage. This indicates that it maybe feasible to extend the expiration period of this vaccine from one year to three years.

• BMB Reports
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• v.44 no.4
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• pp.232-237
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• 2011

Human respiratory syncytial virus (HRSV) is a major cause of upper and lower respiratory tract illness in infants and young children worldwide. Despite its importance as a respiratory pathogen, there is currently no licensed vaccine for prophylaxis of HRSV infection. There are several hurdles complicating the development of a RSV vaccine: 1) incomplete immunity to natural RSV infection leading to frequent re-infection, 2) immature immune system and maternal antibodies of newborn infants who are the primary subject population, and 3) imbalanced Th2-biased immune responses to certain vaccine candidates leading to exacerbated pulmonary disease. After the failure of an initial trial featuring formalin-inactivated virus as a RSV vaccine, more careful and deliberate efforts have been made towards the development of safe and effective RSV vaccines without vaccine-enhanced disease. A wide array of RSV vaccine strategies is being developed, including live-attenuated viruses, protein subunit-based, and vector-based candidates. Though licensed vaccines remain to be developed, our great efforts will lead us to reach the goal of attaining safe and effective RSV vaccines in the near future.