• Proceedings of the Korea Society of Poultry Science Conference
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• 2006.11a
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• pp.90-91
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• 2006

To reduce the economic impact and control Low pathogenic avian influenza (LPAI), vaccination with inactivated vaccine has been considered in this country. We tried to develop inactivated vaccine with reassorted H9N3 AI virus which has different type of neuraminidase compare to those of field AI virus. Before reassorted vaccine was produced, we confirm the virus as master seed by limiting dilution, RT-PCR and sequencing method. Also, we evaluate the biological characteristics of the virus to find out the possibility of prevention against field infection of AI virus. Finally, we evaluate the safety and efficacy of the vaccine made of reassorted AI virus in the specific pathogen free (SPF) chickens. After limiting dilution, we choose RV7CE4 as a vaccine candidate and compare the gene sequence of this vaccine strain to those of AI05GA which is parents strain. Compared to amino acid sequences of specific gene of AI05GA and RV7CE4, exhibited a high degree of amino acid sequence homology. In the safety and efficacy test, there were no specific clinical signs or mortality. Reassorted H9N3 viruses were reisolated in cloaca swab on 5 days post inoculation. In the vaccine study, once or twice vaccination was performed and challenged with H9N2 field virus (01310). Vaccine has no adverse effect on birds and formed good immune capability which reduce viral shedding in the birds infected with 01310. Based on the above result, we developed reassorted H9N3 vaccine which will efficiently prevent the low pathogenic AIV (H9N2) infection in the poultry farms.

• Journal of Microbiology and Biotechnology
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• v.21 no.4
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• pp.405-411
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• 2011

Avian influenza virus vaccines produced in oil-emulsified inactivated form with antigen content of at least 160 hemagglutinin units (HAU) induced immunity in birds. However, in addition to enhancing the effect of the adjuvant(s), other additional supplemented biological compounds included in inactivated vaccines could produce higher levels of antibody. We examined in chickens, Vietnamese ducks, and muscovy ducks the adjuvant effect of Sophy ${\beta}$-glucan (SBG), a ${\beta}$-1,3-1,6 glucan produced by the black yeast Aureobasidium pollulans strain AF0-202, when administered with an avian influenza H5 subtype vaccine. In Experiment 1, 40 chickens (ISA Brown hybrid), allocated to four groups of ten each, were immunized with Oil-H5N1(VN), Oil-H5N1(CN), Oil-H5N2(CN), and saline (control group), respectively. In Experiment 2, chickens (ISA Brown hybrid), muscovy ducks (French hybrid), and Vietnamese ducks (indigenous Vietnamese) were used to further assess the effect of SBG on immunogenicity of the Oil-H5N1(VN) Vietnamese vaccine. ELISA and hemagglutination inhibition (HI) assays were used to assess the antibody response. The H5 subtype vaccines initiated significantly higher immune responses in the animals dosed with SBG, with 1.0-1.5 $log_2$ higher HI titers and 10-20% ELISA seroconversion, compared with those not dosed with ${\beta}$-glucan. Notably, some of the animals dosed with SBG induced HI titers higher than 9.0 $log_2$ following boosting immunization. Taken together, our serial studies indicated that SBG is a potential effector, such as enhancing the immune response to the H5 vaccines tested.

• IMMUNE NETWORK
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• v.16 no.5
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• pp.311-315
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• 2016

A pandemic influenza A (H1N1) virus strain was isolated from a pig farm in Korea in December 2009. The strain was propagated in and isolated from both the Madin-Darby canine kidney cell line and embryonated eggs. The partial and complete sequences of the strain were identical to those of A/California/04/2009, with >99% sequence similarity in the HA, NA, M, NS, NP, PA, PB1, and PB2 genes. The isolated strain was inactivated and used to prepare a swine influenza vaccine. This trial vaccine, containing the new isolate that has high sequence similarity with the pandemic influenza A (H1N1) virus, resulted in seroconversion in Guinea pigs and piglets. This strain could therefore be a potential vaccine candidate for swine influenza control in commercial farms.

• Journal of Microbiology and Biotechnology
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• v.28 no.6
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• pp.997-1006
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• 2018

As shown during the 2009 pandemic H1N1 (A(H1N1)pdm09) outbreak, egg-based influenza vaccine production technology is insufficient to meet global demands during an influenza pandemic. Therefore, there is a need to adapt cell culture-derived vaccine technology using suspended cell lines for more rapid and larger-scale vaccine production. In this study, we attempted to generate a high-growth influenza vaccine strain in MDCK cells using an A/Puerto/8/1934 (H1N1) vaccine seed strain. Following 48 serial passages with four rounds of virus plaque purification in MDCK cells, we were able to select several MDCK-adapted plaques that could grow over $10^8PFU/ml$. Genetic characterization revealed that these viruses mainly had amino acid substitutions in internal genes and exhibited higher polymerase activities. By using a series of Rg viruses, we demonstrated the essential residues of each gene and identified a set of high-growth strains in MDCK cells ($PB1_{D153N}$, $M1_{A137T}$, and $NS1_{N176S}$). In addition, we confirmed that in the context of the high-growth A/PR/8/34 backbone, A/California/7/2009 (H1N1), A/Perth/16/2009 (H3N2), and A/environment/Korea/deltaW150/2006 (H5N1) also showed significantly enhanced growth properties (more than $10^7PFU/ml$) in both attached- and suspended-MDCK cells compared with each representative virus and the original PR8 vaccine strain. Taken together, this study demonstrates the feasibility of a cell culture-derived approach to produce seed viruses for influenza vaccines that are cheap and can be grown promptly and vigorously as a substitute for egg-based vaccines. Thus, our results suggest that MDCK cell-based vaccine production is a feasible option for producing large-scale vaccines in case of pandemic outbreaks.

• Pediatric Infection and Vaccine
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• v.25 no.1
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• pp.35-44
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• 2018

Purpose: This study aimed to evaluate the immunogenicity and safety of a trivalent inactivated influenza vaccine (TIV) among healthy Korean children and adolescents. Methods: From October to December 2008, 65 healthy patients aged 6 months to 18 years who visited Korea University Ansan Hospital for influenza vaccination were enrolled in this study. We measured the hemagglutinin inhibition antibody titers at baseline and 30 days after vaccinating enrollees with split influenza vaccine and calculated the seroprotection rates, geometric mean titers, and seroconversion rates. Local and systemic adverse events were assessed after vaccination. Results: The seroprotection rates against all three viral strains (A/H1N1, A/H3N2, B) were 87.7%, 89.2%, and 89.2% (${\geq}70%$), respectively; seroconversion rates were 44.6%, 73.8%, and 63.1% (${\geq}40%$), respectively; and seroconversion factors were 4.5, 8.4, and 10.5 (>2.5), respectively. The TIV immunogenicity was acceptable according to the CPMP (Committee for Proprietary Medicinal Products) criteria. Although 48 patients (73.8%) reported one or more adverse events, no severe adverse events such as anaphylaxis and convulsion were observed. Forty-two patients (64.6%) reported a local skin reaction, including redness (29.2%), pain (43.1%), or swelling (41.5%) of the injected site, and 26 (40.0%) reported a systemic reaction: fatigue (23.1%), myalgia (20.0%), headache (10.8%), arthralgia (10.8%), chills (9.2%), or fever (7.7%). Conclusions: This study shows that the immunogenicity of the TIV vaccine is acceptable. As there were no serious adverse events aside from local reactions and mild systemic reactions, this vaccine can be safely used among healthy Korean children and adolescents.

• Journal of Veterinary Science
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• v.24 no.1
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• pp.5.1-5.16
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• 2023

The H9N2 avian influenza (AI) has become endemic in poultry in many countries since the 1990s, which has caused considerable economic losses in the poultry industry. Considering the long history of the low pathogenicity H9N2 AI in many countries, once H9N2 AI is introduced, it is more difficult to eradicate than high pathogenicity AI. Various preventive measures and strategies, including vaccination and active national surveillance, have been used to control the Y439 lineage of H9N2 AI in South Korea, but it took a long time for the H9N2 virus to disappear from the fields. By contrast, the novel Y280 lineage of H9N2 AI was introduced in June 2020 and has spread nationwide. This study reviews the history, genetic and pathogenic characteristics, and control strategies for Korean H9N2 AI. This review may provide some clues for establishing control strategies for endemic AIV and a newly introduced Y280 lineage of H9N2 AI in South Korea.

• Korean Journal of Veterinary Research
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• v.52 no.4
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• pp.223-230
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• 2012

The worldwide distribution and continuing genetic mutation of avian influenza virus (AIV) has been posed a great threat to human and animal health. A comparison of 3 isolates of AIV H9N2, A/chicken/Korea/KBNP-0028/00 (H9N2) (KBNP-0028), A/chicken/Korea/SNU8011/08 (H9N2) (SNU 8011) and an inactivated oil vaccine strain A/chicken/Korea/01310/01 (H9N2) (01310), was performed. The former 2 AIVs were isolated from field cases before and after the application of an inactivated H9N2 vaccine in 2007, respectively. The antigenic relationship, viral shedding, tissue tropism and genetic analysis were examined. The comparison of virus shedding from the cloaca and the oropharynx revealed that both isolates were more frequently isolated from the upper respiratory tract (90~100%) 1 day post inoculation (DPI) compared with isolation 5 DPI from gastrointestinal tracts (10~60%). Moreover, the isolate KBNP-0028 were recovered from all organs including bone marrow, brain and kidneys, indicating higher ability for broad tissue dissemination than that of SNU 8011. KBNP-0028 replicated earlier than other strains and with a higher titer than SNU 8011. In full-length nucleotide sequences of the NA gene and a partial sequence of the HA gene of SNU 8011, we found that there might be significant changes in tissue tropism, virus replication and genetic mutation in AIV H9N2 isolates.

• Journal of Life Science
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• v.20 no.3
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• pp.365-373
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• 2010

To monitor newly emerged influenza virus variants and to investigate the prevalence pattern, our laboratory performed isolation of the viruses from surveillance sentinel hospitals. In the present study, we analysed influenza A/H1N1, A/H3N2, B viruses isolated in Busan during the 2006/07 and 2007/08 seasons by sequence analysis of the hemagglutinin (HA1 subunit) and neuraminidase (NA) genes. The isolates studied here were selected by the stratified random sample method from a total of 277 isolates, in which 15 were A/H1N1, 16 were A/H3N2 and 29 were B. Based on the phylogenetic tree, the HA1 gene showed that A/H1N1 isolates had a 96.7% to 97.7% homology with the A/Brisbane/59/2007, A/H3N2 isolates had a 98.4% to 99.7% homology with the A/Brisbane/10/2007, and B isolates had a 96.5% to 99.7% homology with the B/Florida/4/2006(Yamagata lineage), which are all the vaccine strains for the Northern Hemisphere in 2008~2009 season. In the case of the NA gene, A/H1N1 isolates had 97.8% to 98.5% homologies, A/H3N2 isolates had 98.9% to 99.4% homologies, and B isolates had 98.9% to 100% homologies with each vaccine strain in the 2008~2009 season, respectively. Characterization of the hemagglutinin gene revealed that amino acids at the receptor-binding site and N-linked glycosylation site were highly conserved. These results provide useful information for the control of influenza viruses in Busan and for a better understanding of vaccine strain selection.

• Journal of Microbiology and Biotechnology
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• v.17 no.5
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• pp.868-872
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• 2007

H1N2 influenza viruses are circulating in pigs worldwide and cause considerable economic losses to the pig industry. We genetically analyzed the genes of our isolates from Korean pigs, and compared the antigenicity of our isolates with swine H1N2 viruses isolated from pigs in the U.S.A. In addition, we serologically surveyed the infection rate of swine H1N2 viruses in pigs. We found that H1N2 isolates from Korean pigs are genetically more related to swine H1N2 viruses isolated from pigs in the U.S.A. than those in European countries. When antigenicity was compared, our isolates were weakly reacted to antibodies against swine H1N2 viruses isolated from pigs in the U.S.A. The serological surveillance using sera from pigs in Korea showed that about 46% was positive for H1N2 viruses. Our results suggest that swine H1N2 viruses are widespread in Korean pigs, and the development of a vaccine against H1N2 viruses may help to control their infection in pigs.

• Clinical and Experimental Pediatrics
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• v.54 no.10
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• pp.422-424
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• 2011

Acute disseminated encephalomyelitis (ADEM) is an inflammatory demyelinating disease of the central nervous system that typically follows an infection or vaccination and has a favorable long-term prognosis. We describe the first reported case of ADEM after vaccination against novel influenza A (H1N1). A previously healthy 34-month-old boy who developed ADEM presented with a seizure and left-sided weakness 5 days after vaccination against novel influenza A (H1N1). Cerebrospinal fluid examination revealed elevated cell counts. T2-weighted images and fluid-attenuated inversion recovery images revealed multiple patchy hyperintense lesions in the frontal and parietal subcortical white matter and the left thalamus. After the administration of intravenous corticosteroid, the patient's clinical symptoms improved and he recovered completely without neurologic sequelae.