• Clinical and Experimental Pediatrics
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• v.49 no.3
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• pp.229-234
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• 2006

Varicella, which is mostly a benign disease, but also can cause considerable health burden in the community, can be prevented by immunization with live attenuated varicella vaccine. Higher uptake of varicella vaccine by universal immunization in North America has apparently been associated with decline in the number of reported cases of varicella, varicella-related hospitalizations, and the number of deaths caused by complications of varicella. On the contrary, there has been some reluctance in endorsing varicella vaccine for universal immunization in most of European countries. Concerns include unanticipated outbreaks of varicella among vaccine recipients, risk of varicella among unvaccinated adults, risk of herpes zoster among vaccinees as well as unvaccinees. Recently developed measles, mumps, rubella, and varicella combination vaccine and herpes zoster vaccine that may be licensed in the upcoming years may be the solution for varicella vaccine to be utilized in a greater scale. In Korea several varicella vaccine products have been utilized since late 1980. The adoption of varicella vaccine for universal immunization since 2005 along with the changing view in varicella prevention strategy mandates more studies for immunogenecity and efficacy of varicella vaccines as well as more surveillance to delineate the changes in epidemiology of varicella in Korea.

• IMMUNE NETWORK
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• v.21 no.4
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• pp.28.1-28.14
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• 2021

Lung-resident memory T cells (T_RM) play an essential role in protecting against pulmonary virus infection. Parenteral administration of DNA vaccine is generally not sufficient to induce lung CD8 T_RM cells. This study investigates whether intramuscularly administered DNA vaccine expressing the nucleoprotein (NP) induces lung T_RM cells and protects against the influenza B virus. The results show that DNA vaccination poorly generates lung T_RM cells and massive secondary effector CD8 T cells entering the lungs after challenge infection do not offer sufficient protection. Nonetheless, intranasal administration of non-replicating adenovirus vector expressing no Ag following priming DNA vaccination deploys NP-specific CD8 T_RM cells in the lungs, which subsequently offers complete protection. This novel 'prime and deploy' strategy could be a promising regimen for a universal influenza vaccine targeting the conserved NP Ag.

• Pediatric Infection and Vaccine
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• v.15 no.1
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• pp.12-19
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• 2008

Varicella is a highly infectious disease caused by the varicella zoster virus. The varicella vaccine was developed by Michiaki Takahashi in Japan in 1974. Despite the worldwide distribution of efficient vaccines, varicella vaccination policy is extremely variable from country to country. Although varicella vaccine is not currently recommended for universal vaccination in Japan, most countries throughout Europe, and developing countries, it had been introduced into Korea in 1988 and 20 years have elapsed since its use. Currently, varicella vaccine has been most extensively used in the United States where routine 2-dose vaccination program has been recently implemented for children. Recent 2-dose schedule in the United States and the availability of combination measles-rubella-varicella vaccines may lead to future varicella vaccination policy changes in many countries. With this background, this article summarizes the current status of varicella vaccination policies worldwide and presents provisional updated recommendation of varicella vaccination in Korea.

• IMMUNE NETWORK
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• v.23 no.4
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• pp.32.1-32.15
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• 2023

Most influenza vaccines currently in use target the highly variable hemagglutinin protein to induce neutralizing antibodies and therefore require yearly reformulation. T cell-based universal influenza vaccines focus on eliciting broadly cross-reactive T-cell responses, especially the tissue-resident memory T cell (T_RM) population in the respiratory tract, providing superior protection to circulating memory T cells. This study demonstrated that intramuscular (i.m.) administration of the adenovirus-based vaccine expressing influenza virus nucleoprotein (rAd/NP) elicited weak CD8 T_RM responses in the lungs and airways, and yielded poor protection against lethal influenza virus challenge. However, a novel "prime-and-deploy" strategy that combines i.m. vaccination of rAd/NP with subsequent intranasal administration of an empty adenovector induced strong NP-specific CD8⁺ T_RM cells and provided complete protection against influenza virus challenge. Overall, our results demonstrate that this "prime-and-deploy" vaccination strategy is potentially applicable to the development of universal influenza vaccines.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6481-6484
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• 2012

Background: In 2008, the Health Authority in Abu Dhabi (the capital of the United Arab Emirates) introduced HPV vaccine free of charge for high school girls entering grade 11, becoming the first state in the Middle East to do so. The objectives of this study were to assess the knowledge, attitude and practice of school nurses in the Emirate of Abu Dhabi about HPV infection and the vaccine. Materials and Methods: A quantitative study was designed and conducted from June to August 2012 in Emirate of Abu Dhabi. Data were collected through direct face to face interviews. from one hundred and twenty five nurses. Results: Knowledge of HPV infection and HPV vaccine was almost universal among the school nurses (97%). The majority of the participants (71%) thought that the HPV vaccine was good. Cultural unacceptability (45%) and lack of women's concern about their own health (21%) were rated as the top barriers for the successful introduction of the vaccine in the UAE. More than half of the sampled nurses (58%) have either given this vaccine to school girls or taken it themselves. The majority (95%) did not come across any side effects from the vaccine. The level of qualification and the place of work did not significantly affect the correct knowledge of HPV infection or cervical cancer prevention methods. Conclusions: The knowledge and attitude of the sampled school nurses in Abu Dhabi State about HPV infection and vaccine is very good in both the public and private sectors. However, a knowledge gap in cervical cancer screening methods was identified.

• 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.

• IMMUNE NETWORK
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• v.24 no.3
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• pp.19.1-19.15
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• 2024

The influenza virus poses a global health burden. Currently, an annual vaccine is used to reduce influenza virus-associated morbidity and mortality. Most influenza vaccines have been developed to elicit neutralizing Abs against influenza virus. These Abs primarily target immunodominant epitopes derived from hemagglutinin (HA) or neuraminidase (NA) of the influenza virus incorporated in vaccines. However, HA and NA are highly variable proteins that are prone to antigenic changes, which can reduce vaccine efficacy. Therefore, it is essential to develop universal vaccines that target immunodominant epitopes derived from conserved regions of the influenza virus, enabling cross-protection among different virus variants. The internal proteins of the influenza virus serve as ideal targets for universal vaccines. These internal proteins are presented by MHC class I molecules on Ag-presenting cells, such as dendritic cells, and recognized by CD8 T cells, which elicit CD8 T cell responses, reducing the likelihood of disease and influenza viral spread by inducing virus-infected cell apoptosis. In this review, we highlight the importance of CD8 T cell-mediated immunity against influenza viruses and that of viral epitopes for developing CD8 T cell-based influenza vaccines.

• Journal of Preventive Medicine and Public Health
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• v.56 no.2
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• pp.172-179
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• 2023

Objectives: Vaccination is an important intervention for preventing disease and reducing disease severity. Universal vaccination programs have significantly reduced the incidence of many dangerous diseases among children worldwide. This study investigated the side effects after immunization in infants under 1 year of age in Lorestan Province, western Iran. Methods: This descriptive analytical study included data from all children <1 year old in Lorestan Province, Iran who were vaccinated according to the national schedule in 2020 and had an adverse event following immunization (AEFI). Data were extracted from 1084 forms on age, sex, birth weight, type of birth, AEFI type, vaccine type, and time of vaccination. Descriptive statistics (frequency, percentage) were calculated, and the chi-square test and Fisher exact test were used to assess differences in AEFIs according to the abovelisted variables. Results: The most frequent AEFIs were high fever (n=386, 35.6%), mild local reaction (n=341, 31.5%), and swelling and pain (n=121, 11.2%). The least common AEFIs were encephalitis (n=1, 0.1%), convulsion (n=2, 0.2%), and nodules (n=3, 0.3%). Girls and boys only showed significant differences in mild local reactions (p=0.044) and skin allergies (p=0.002). The incidence of lymphadenitis (p<0.001), severe local reaction (p<0.001), mild local reaction (p=0.007), fainting (p=0.032), swelling and pain (p=0.006), high fever (p=0.005), and nodules (p<0.001) showed significant differences based on age at vaccination. Conclusions: Immunization is a fundamental public health policy for controlling vaccine-preventable infectious diseases. Although vaccines such as the Bacillus Calmette-Guérin vaccine, oral poliovirus vaccine, and pentavalent vaccine are well-researched and reliable, AEFIs are inevitable.

• Clinical and Experimental Pediatrics
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• v.65 no.3
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• pp.108-114
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• 2022

The Japanese encephalitis (JE) virus is the leading cause of vaccine-preventable encephalitis in Asia. Since the introduction of a universal JE vaccination program and urbanization of Korea, the incidence of JE has dramatically decreased in Korea. However, recent JE cases have occurred, predominantly among unvaccinated adults and with a shift in age distribution. Here we aimed to review the changes in age-specific JE seroprevalence over time and discuss the implications of JE vaccination programs in Korea. Following the last epidemic in 1982-1983, mandatory vaccination for all children aged 3-15 years was conducted annually until 1994. However, JE has reemerged, predominantly affecting unvaccinated adults aged 40 years or older and demonstrating a shift in age distribution toward older populations. The age-specific seroprevalence of the JE virus in Korea has changed noticeably over time. Seropositivity in children and adolescents increased from 10%-59% in the 1970s to 90%-92% in the 1980s after the implementation of the JE vaccination program and increased further to 98% in 2012. No age-specific difference in the seroprevalence of JE was found, and appropriate levels of immunity to JE were maintained for all age groups. Continuous surveillance of the seroprevalence of JE is essential to establish a proper immunization policy in Korea.

• Clinical and Experimental Pediatrics
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• v.51 no.7
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• pp.696-703
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• 2008

Korea is now classified as an area of intermediate endemicity for hepatitis B virus (HBV), due to the implementation of universal HBV vaccination and national preventive programs for HBV infection. A national program of HBV vaccination was launched in Korea in 1988 for school-going children and was listed on a vaccination guideline in 1991. In 1995, universal vaccination for newborn infants was started for the prevention of perinatal HBV transmission. The prevalence of HBsAg among Korean middle school students has shown marked decreased from 3.2% in the late 1990s to 0.44% in 2007. HBsAg positivity in preschool children was 0.9% in 1995, decreased to 0.2% in 2007 by national prevention program of hepatitis B vertical transmission, launched in 2002. Vaccine failure rate of HBV immunoprophylaxis is 4.2% by this program. The infected children should be monitored per 6-12 months interval. Lamivudine and interferon are approved therapies for children with chronic hepatitis B in immune-clearance phase in Korea.