• Journal of Microbiology and Biotechnology
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• v.31 no.2
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• pp.304-316
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• 2021

Vaccination is the most effective way to prevent influenza virus infections. However, conventional vaccines based on hemagglutinin (HA) have to be annually updated because the HA of influenza viruses constantly mutates. In this study, we produced a 3M2e-3HA2-NP chimeric protein as a vaccine antigen candidate using an Escherichia coli expression system. The vaccination of chimeric protein (15 ㎍) conferred complete protection against A/Puerto Rico/8/1934 (H1N1; PR8) in mice. It strongly induced influenza virus-specific antibody responses, cytotoxic T lymphocyte activity, and antibody-dependent cellular cytotoxicity. To spare the dose and enhance the cross-reactivity of the chimeric, we used a complex of poly-γ-glutamic acid and alum (PGA/alum) as an adjuvant. PGA/alum-adjuvanted, low-dose chimeric protein (1 or 5 ㎍) exhibited higher cross-protective effects against influenza A viruses (PR8, CA04, and H3N2) compared with those of chimeric alone or alum-adjuvanted proteins in vaccinated mice. Moreover, the depletion of CD4+ T, CD8+ T, and NK cells reduced the survival rate and efficacy of the PGA/alum-adjuvanted chimeric protein. Collectively, the vaccination of PGA/alum-adjuvanted chimeric protein induced strong protection efficacy against homologous and heterologous influenza viruses in mice, which suggests that it may be a promising universal influenza vaccine candidate.

• Pediatric Infection and Vaccine
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• v.27 no.1
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• pp.53-61
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• 2020

Purpose: To compare differences and changes in the parents' awareness regarding influenza and influenza vaccination for their children according to educational intervention. Methods: This study involved 1,034 parents with children aged 6-59 months, who lived in five areas in northern Seoul and Gyeonggi Province in 2015; the study was conducted using the questionnaire survey method. Survey items included awareness regarding influenza and influenza vaccination for children and future intentions of influenza vaccination and the underlying reasons. The participants were divided into 3 groups and differences according to education (group A: no education, group B: provided education) and the changes before and after education (group C) were analyzed. Results: Differences according to education between groups A and B were seen in the recognition of high-risk of influenza in their children, effectiveness of influenza vaccination, and cost of the influenza vaccine. Changes before and after education in group C were seen in the recognition of high-risk of influenza in their children, safety of influenza vaccination, cost of the influenza vaccine, and negativity toward the influenza vaccine. Conclusions: Educated parents were more aware regarding influenza and influenza vaccination for their children aged 6-59 months.

• Child Health Nursing Research
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• v.24 no.2
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• pp.148-156
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• 2018

Purpose: The aim of this study was to evaluate the influence of the mothers' native country on influenza vaccinations in adolescents in multicultural families. Methods: Data were gathered from the 13th (2017) Youth Risk Behavior Web-Based Survey. Logistic regression analyses were conducted using a complex sample data analysis method. The participants in this study had a father who was born in Korea and a mother born outside of Korea. The sample included 481 adolescents. Results: The analysis of non-adjusted confounding variables showed that influenza vaccination was higher in multicultural adolescents whose mother's native country had an annual minimum temperature less than $21^{\circ}C$ (odds ratio [OR]: 1.81, 95% confidence interval [CI]: 1.20~2.74). Furthermore, when the analysis was adjusted for confounding variables, an annual minimum temperature less than $21^{\circ}C$ in the mother's native country had a statistically significant association with influenza vaccination (OR: 2.12, 95% CI: 1.36~3.29). Conclusion: Multicultural adolescents belong to a socioeconomically vulnerable class, and their health promotion behaviors are influenced by their mothers' culture. Thus, healthcare providers and school nurses should provide adolescents with appropriate information related to influenza vaccination depending on their mothers' culture and their family's cultural background.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.1
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• pp.128-133
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• 2000

This study was designed to verify the efficacy of garlic extracts for protecting the infecton of influenza and Japanese B encephalitis virus. Influenza virus (AO/PR8 strain) and Japanese B encephalitis virus (JaGAr O1 strain) were used to attack mouse through nasal route and each vaccines were injected subcutaneously. 0.002 and 0.2 mL/day of garlic extracts were orally administered to mice. The blood and serum samples were taken from the mice to measure LD50, Defense Index (DI), virus-neutralizing antibody for comparing virus influence inhibiting activities. Defense indices of the male and female mice were not significantly different at every experiment. Vaccination effectively inhibited the influence of influenza virus and 0.002 mL/day garlic extract (0.55$\pm$0.05) resulted in significantly higher DI than the control (0$\pm$0.05) (p<0.05). Although 0.002 mL/day garlic extract (0.55$\pm$0.05) resulted in significantly lower DI than the vaccination (1.10$\pm$0.05), 0.2 mL/day garlic extract (2.05$\pm$0.05) resulted in 10 times higher DI than the vaccination (1.10$\pm$0.05). Garlic extract did not affect DI in Japanese B encephalitis virus influence of the vaccinated mouse, but significantly reduced DI of the non-vaccinated mouse (p<0.05). Garlic extracts did not affect the production of the neutralizing antibody against influenza by vaccination. However, neutralizing antibody production of Japanese B encephalitis was accelerated by vaccination. Consequently, the current study proved the efficacy of garlic on inhibition of influenza virus. Finally, it is very hard to show the higher preventing effect on flu through ingestion of garlic as a food than vaccination.

• Journal of Korean Academy of Nursing
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• v.41 no.3
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• pp.403-410
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• 2011

Purpose: This study was to identify the current status of vaccination against the pandemic (H1N1) 2009 virus among university students from the fields of nursing and allied health from a local community and verify factors influencing vaccination. Methods: The study included 227 students in the fields of nursing and allied health from a provincial university. Data were obtained from these participants between May 31 and June 11, 2010 by using self-report questionnaires. Results: The rate of vaccination against the pandemic (H1N1) 2009 virus for these participants was 14.5%. No difference was observed in this regard between majors and school year. Factors that influence vaccination against this virus included previous vaccination against seasonal influenza and participants’ attitudes toward general vaccination. Conclusion: The results suggest that for effective pandemic (H1N1) 2009 vaccination of university students from the fields of nursing and allied health, students who have not been vaccinated should be intensively managed. Developing a vaccination program that encourages a positive attitude toward vaccination is recommended.

• Parasites, Hosts and Diseases
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• v.56 no.5
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• pp.429-435
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• 2018

Toxoplasma gondii is a ubiquitous protozoan parasite responsible for causing toxoplasmosis. Preventive measures for toxoplasmosis are currently lacking and as such, development of novel vaccines are of urgent need. In this study, we generated 2 virus-like particles (VLPs) vaccines expressing T. gondii rhoptry protein 4 (ROP4) or rhoptry protein 18 (ROP18) using influenza matrix protein (M1) as a core protein. Mice were intranasally immunized with VLPs vaccines and after the last immunization, mice were challenged with ME49 cysts. Protective efficacy was assessed and compared by determining serum antibody responses, body weight changes and the reduction of cyst counts in the brain. ROP18 VLPs-immunized mice induced greater levels of IgG and IgA antibody responses than those immunized with ROP4 VLPs. ROP18 VLPs immunization significantly reduced body weight loss and the number of brain cysts in mice compared to ROP4 VLPs post-challenge. These results indicate that T. gondii ROP18 VLPs elicited better protective efficacy than ROP4 VLPs, providing important insight into vaccine design strategy.

• Pediatric Infection and Vaccine
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• v.26 no.3
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• pp.161-169
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• 2019

Purpose: This study was conducted to compare immunogenicities and reactogenicities of the trivalent inactivated subunit influenza vaccine and split influenza vaccine in Korean children and adolescents. Methods: In total, 202 healthy children aged 36 months to <18 years were enrolled at six hospitals in Korea from October to December 2008. The subjects were vaccinated with either the split or subunit influenza vaccine. The hemagglutinin inhibition antibody titers against the H1N1, H3N2, and B virus strains were measured, and the seroconversion rates, seroprotection rates, and geometric mean titers were calculated. All subjects were observed for local and systemic reactions. Results: Both the split and subunit vaccine groups had similar seroprotection rates against all strains (95.9%, 94.9%, 96.9% vs. 96.0%, 90.9%, and 87.9%). In children aged 36 to <72 months, the seroprotection rates were similar between the two vaccine groups. In children aged 72 months to <18 years, both vaccines showed high seroprotection rates against the H1N1, H3N2, and B strain (98.4%, 98.4%, 98.4% vs. 97.0%, 95.5%, and 91.0%), but showed relatively low seroconversion rates (39.1%, 73.4%, 35.9% vs. 34.3%, 55.2%, and 38.8%). There were more local and systemic reactions in the split vaccine group than in the subunit vaccine group; however, no serious adverse reactions were observed in both groups. Conclusions: Both the split and subunit vaccines showed acceptable immunogenicity in all age groups. There were no serious adverse events with both vaccines.

• Pediatric Infection and Vaccine
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• v.24 no.1
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• pp.7-15
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• 2017

Purpose: Influenza vaccination coverage in adolescents is an important goal of informed vaccination policies and programs. This study aimed to estimate the influenza vaccination coverage rate and investigate the factors influencing influenza vaccination coverage in Korean adolescents. Methods: The study population consisted of 5,213 adolescents (aged 12 to 18 years) who participated in the Korea National Health and Nutrition Examination Survey from 2007 to 2014 (except for 2013). We analyzed influenza vaccination coverage in relation to the demographics, lifestyle, and medical characteristics of the participants. Results: The influenza vaccination coverage rate, during the study period, was 23.2% (range, 21.1% to 24.7%). Logistic regression analysis revealed that factors influencing influenza vaccination were elementary school age (odds ratio [OR], 1.706; 95% confidence interval [CI], 1.526 to 1.906), good self-rated health status (OR, 1.192; 95% CI, 1.057 to 1.344), a drinking status of non-drinker (OR, 1.769; 95% CI, 1.474 to 2.122), a smoking status of non-smoker (OR, 1.459; 95% CI, 1.144 to 1.860), and a past diagnosis of pneumonia (OR, 1.469; 95% CI, 1.076 to 2.006). Conclusions: Influenza vaccination coverage in Korean adolescents is relatively low. Special efforts are needed to increase vaccination coverage for adolescent groups with low vaccination rates including adolescent smokers and drinkers, middle and high school age adolescents, and adolescents with a poor self-rated health status.

• Journal of Preventive Medicine and Public Health
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• v.43 no.2
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• pp.109-116
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• 2010

Objectives: The pandemic of novel influenza A (H1N1) virus has required decision-makers to act in the face of the substantial uncertainties. In this study, we evaluated the potential impact of the pandemic response strategies in the Republic of Korea using a mathematical model. Methods: We developed a deterministic model of a pandemic (H1N1) 2009 in a structured population using the demographic data from the Korean population and the epidemiological feature of the pandemic (H1N1) 2009. To estimate the parameter values for the deterministic model, we used the available data from the previous studies on pandemic influenza. The pandemic response strategies of the Republic of Korea for novel influenza A (H1N1) virus such as school closure, mass vaccination (70% of population in 30 days), and a policy for anti-viral drug (treatment or prophylaxis) were applied to the deterministic model. Results: The effect of two-week school closure on the attack rate was low regardless of the timing of the intervention. The earlier vaccination showed the effect of greater delays in reaching the peak of outbreaks. When it was no vaccination, vaccination at initiation of outbreak, vaccination 90 days after the initiation of outbreak and vaccination at the epidemic peak point, the total number of clinical cases for 400 days were 20.8 million, 4.4 million, 4.7 million and 12.6 million, respectively. The pandemic response strategies of the Republic of Korea delayed the peak of outbreaks (about 40 days) and decreased the number of cumulative clinical cases (8 million). Conclusions: Rapid vaccination was the most important factor to control the spread of pandemic influenza, and the response strategies of the Republic of Korea were shown to delay the spread of pandemic influenza in this deterministic model.

• Korean Journal of Clinical Laboratory Science
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• v.54 no.2
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• pp.103-109
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• 2022

In December 2019, the coronavirus disease 2019 (COVID-19) caused by the virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in China and spread rapidly around the world, infecting millions of people. Cases of COVID-19 infection were observed to lead to viral pneumonia. Thirty-five patients admitted to the Gyeonggi Medical Center, South Korea, between November 2020 to January 2021, were found to have been infected with the influenza virus A and B, which cause symptoms similar to COVID-19. The records of these patients and those of COVID-19 patients who visited the hospital for medical examination were compared. The study patients included thirty patients with COVID-19 and/or influenza, five of those with influenza alone. A group of 121 patients without infection was used as control. Patients with COVID-19 and influenza had significantly higher lactate dehydrogenase levels than the patients with COVID-19 alone. The erythrocyte sedimentation rate (ESR) was higher in patients with COVID-19 alone than in other groups. Significant clinical outliers were observed in the COVID-19 and influenza infection group compared with the COVID-19 alone group. These results are expected to play an important role in the analysis of the hematological data of infected patients and the comparison of simultaneous and single infection data to determine clinical symptoms and other signs. These results may also assist in the development of vaccines and treatments for COVID-19.