• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.12 no.sup1
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• pp.72-76
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• 2009

Rotavirus infection is the leading cause of severe diarrhea disease in infants and young children worldwide. Rotavirus infects every child at least once by her/his $5^{th}$ birthday. It has been known that single episode of rotavirus infection can protect or alleviate subsequent illness caused by both homotypic and heterotypic rotaviruses. There are two currently licensed rotavirus vaccines. One is human-bovine rotavirus reassortant pentavalent vaccine ($RotaTeq^{TM}$), which contains five reassortant rotavirus (expressing protein G1, G2, G3, G4 and P[8]) and was licensed in Korea for use among infants in 2007. Another is live-attenuated human rotavirus vaccine ($Rotarix^{TM}$) derived from 89-12 strain which represents the most common of the human rotavirus VP7(G1) and VP4(P[8]) antigens. $Rotarix^{TM}$ was licensed in Korea in 2008. Both live oral rotavirus vaccines are efficacious in preventing severe rotavirus gastroenteritis.

• Journal of Microbiology and Biotechnology
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• v.14 no.1
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• pp.35-40
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• 2004

Rotavirus virus-like particle (VLP) composed of VP2, VP6, and VP7 was expressed in the Baculovirus Expression Vector System (BEVS). Sf9 cell, a host of the baculovirus, was cultured from a 0.5-1 spinner flask to the 50-1 bioreactor system. Sf9 cell was maintained at cell density between 3.0E＋05 and 3.0E＋06 cells/ml and grew up to 1.12E＋07 cells/ml in the bioreactor. Growth kinetics was compared under different culture systems and showed similar growth kinetics with 20.1-25.2 h of doubling time. Early exponentially growing cell culture was infected with three recombinant baculoviruses expressing VP2, VP6, and VP7 protein at 1.0, 2.0, and 0.2 moi, respectively. The expression of rotavirus proteins was confirmed by Western blot analysis and its three-layered virus-like structure was observed under an electron microscope. Rotavirus VLP was semipurified and immunized in ICR mice intramuscularly. Rotavirus-specific serum antibody was detected from 2 weeks after the immunization and lasted at least 21 weeks of the post-immunization, indicating its possible use as a vaccine candidate.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.207-209
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• 2005

Serum is a potential source of bacterial, mycoplasmal and viral contamination, and it has a possibility of the introduction of serum proteins, prion and pyrogens into the final vaccine product. For porcine Rotavirus vaccine production, it is necessary to develop serum free medium which do not cause those problems. A new serum free medium was developed for porcine Rotavirus vaccine based on DMEM, and the performance of developed serum free medium was evaluated in terms of Vero cell growth and Rotavirus vaccine production. The cell density, gown in serum free medium developed, was similar with that in serum supplemented medium. Also, it was higher than that in other commercially available serum free medium. The productivity of Rotavirus vaccine using serum free medium developed and optimum production strategies will be also discussed.

• Pediatric Infection and Vaccine
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• v.15 no.1
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• pp.5-11
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• 2008

Primary rotavirus gastroenteritis infection usually occurs in infants under 2 years of age worldwide regardless of level of hygiene, quality of water, food or sanitation or type of behavior. In Korea, the disease mostly occurred in infants under 2 year old, and usually in late fall to early winter with the highest incidence shown in November until early 1990s. However, since then, relatively the age incidence of this infection has increased in children over 2 years old, and it has mainly occurred in late winter to early spring with the highest incidence shown between February and March. And rotavirus gastroenteritis serotypes varied year to year as well as varied by year within the same region in our country. The comparison of severity scores between age groups in Korea showed that severity score was lowest in infants less than 3 months and highest in infants more than 6 months and less than 12 months, and hospitalization period between age groups was longest in infants older than 3 months and less than 3 months and highest in infants more than 6 months and less than 12 months and less than 6 months. In this aspect, rotavirus vaccines should be given to infants less than 2 years of age in whom the incidence of rotavirus gastroenteritis is the highest, and vaccination should be ideally started before 3 months considering hospitalization period and severity of rotavirus gastroenteritis. However, It should be careful for the introduction of new rotavirus vaccine, and the effectiveness of rotavirus vaccines should be assessed by long-term post marketing surveillance. And we guess an multivalent vaccine may be an ideal rotavirus vaccine to prevent primary infection caused by variable rotavirus strains in Korea. In addition, clinical epidemiology studies on rotavirus gastroenteritis which evaluate the age and serotypes related severity should be continuously conducted in various regions.

• Pediatric Infection and Vaccine
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• v.16 no.2
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• pp.115-122
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• 2009

Diarrhea is one of the most common causes of morbidity and mortality in children worldwide. Rotavirus is the most common cause of infectious diarrhea both in developed and developing countries. However, bacterial causes such as Salmonella typhi and Vibrio cholerae still play an important role in developing countries. Newly developed vaccines for rotavirus, S. typhi, and V. choleae are highly immunogenic and safe in children.

• Pediatric Infection and Vaccine
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• v.25 no.1
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• pp.26-34
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• 2018

Purpose: This study aimed to investigate the changes in the occurrence of rotavirus gastroenteritis (RGE) after the introduction of rotavirus vaccine and estimate rotavirus vaccine effectiveness in hospitalized children. Methods: We compared the retrospective data of 671 patients with acute gastroenteritis (AGE) admitted to the Department of Pediatrics, Hanyang University Seoul Hospital from January 1, 2014, to December 31, 2015, with retrospective data of 1,243 patients admitted to the same institution with AGE from January 1, 2004, to December 31, 2005. The vaccine effectiveness was estimated using a case-positive control test-negative study. Results: The proportion of RGE in AGE was significantly lower in 2014 to 2015 (9.0%, 48/531) than in 2004 to 2005 (22.7%, 282/1,243) (P<0.001). In particular, there was a significant decrease in the 6- to 11-, 12- to 23-, and 24- to 35-month-old groups (P<0.001), whose rotavirus vaccination rates were higher than the remaining age groups. The monthly distribution of patients with RGE in 2004 to 2005 was higher from November to May, peaked in January, followed by December and February. In 2014 to 2015, the monthly distribution of patients with RGE slightly peaked in January. In 2014 to 2015 study, the complete rotavirus vaccination rate was 66.0% (332/503) and incomplete vaccination rate was 6.2% (31/503). Presumed rotavirus vaccine effectiveness was 83.3% (95% confidence interval [CI], 60.5% to 92.9%) in the complete vaccination group and 27.4% (95% CI, -163.7% to 80.0%) in the incomplete group. Conclusions: The proportion of RGE in AGE has markedly decreased since the introduction of rotavirus vaccines, and improving vaccination coverage will further reduce the burden of RGE in Korea.

• Journal of Yeungnam Medical Science
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• v.32 no.2
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• pp.80-84
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• 2015

Background: Rotavirus is the most common cause of severe gastroenteritis in children <5 years of age. The first vaccine, RotaShield was developed, but withdrawn because of its association with increased risk of intussusception. Then, RotaTeq and Rotarix were developed. Although in pre-licensure studies, they were not associated with an increased risk of intussusceptions, in recent studies, it has been controversial. Regarding increased risk of intussusception, we studied the difference in the age of intussusception after rotavirus vaccination. Methods: A retrospective analysis was conducted on 136 patients diagnosed with intussusception at Yeungnam University Medical Center for 4 years in the pre-vaccination period (group A) and in the post vaccination period (group B). Sex, mean age and age distribution of intussusceptions were compared according to the type of rotavirus vaccine (group B-1, RotaTeq; group B-2, Rotarix). Results: The median ages of group A and group B were $18.8{\pm}19.6months$ and $15.5{\pm}10.2months$, with no significant differences (p=0.23). The median ages of group B-1 and group B-2 were $15.3{\pm}9.3months$ and $15.6{\pm}10.8months$, with no significant differences (p=0.91). And No significant difference in the distribution of onset age was observed between groups, and only 6 patients were diagnosed with intussusceptions within 1 month after vaccination. Conclusion: No difference was observed in the distribution of onset age of intussusception after rotavirus vaccination and according to the type of rotavirus vaccine. Our study has a limitation in that it was conducted in part of the Daegu area. Additional study is needed.

• Clinical and Experimental Pediatrics
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• v.56 no.11
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• pp.465-473
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• 2013

The epidemiology of human group A rotavirus was analyzed by examining genotypic data acquired from 1989 to 2009 in South Korea. This information was derived from all the available published articles on rotavirus studies in South Korea, retrieved from both the PubMed and KoreaMed databases. Four common G types (G1, G2, G3, and G4) and three common P types (P[8], P[4], and P[6]) accounted for approximately 93% and 99% of the rotavirus reports, respectively. The G9 type was frequently detected after 2000, and because of this prevalence, it is considered to be the fifth most important G type rotavirus after the G1-G4 genotypes. Less common G types of the virus such as G12, G11, and G10 were detected in some geographic settings, and it is important to consider the context of these subtypes and their epidemiological significance. The P[9] virus genotype was observed in the study and has been discussed in many other studies; however, the P[3], P[10] and P[25] genotypes were rarely detected in the epidemiological research. In general, the distributions of the G and P genotypes showed temporal and geographical fluctuations, and a nationwide rotavirus vaccine program that targeted these genotypes demonstrated effectiveness in protecting against the circulating rotavirus strains. However, further analysis is needed to determine the true long-term effectiveness of these vaccines; the analysis should also consider the unexpected effects of vaccinations, such as vaccineinduced diseases, herd immunity, and changes in host susceptibilities.

• Biomedical Science Letters
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• v.12 no.3
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• pp.209-215
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• 2006

The mutability and frequency of genetic reassortment characteristic of rotavirus and resultant antigenic changes make the rotavirus formidable challenges for control efforts such as the vaccine development. An alternative approach to overcome these difficulties in development of the rotavirus vaccine is to develop effective inhibitors of the virus infection. As an effort to achieve this, effects of glycyrrhetinic acid (GA), which is an active component of glycyrrhizin, on MA-14 cell infection were examined by employing the human rotavirus isolated from Korea, K-21. The data obtained showed that MA-104 cell infection of the K-21 rotavirus was greatly influenced by the presence of both $18{\alpha}-Ga\;and\;18{\beta}-GA$. Both types of GA have inhibited more than 60% of the rotaviral infection at the concentration of 7.68mM. This inhibition effect became much more evident at the higher concentrations of GA. However, the type of GA did not make much differences on the inhibition effect of the drug. Although GA has to be used in high concentrations to exhibit anti-viral activity and to be virostatic, a long history of safe and high dose usage of licoriece in clinical settings in the Far East makes the GA as an attractive inhibitor of the rotaviral infection.

• Pediatric Infection and Vaccine
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• v.21 no.3
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• pp.167-173
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• 2014

Purpose: This study aimed to examine the changes in the outbreak of acute gastroenteritis, rotavirus gastroenteritis after the introduction of the rotavirus vaccine in Korea. Methods: The current study investigated the number of inpatients in the pediatric ward of Inje University Sanggye Paik Hospital during the periods of 2005-2006 and 2011-2012. A retrospective analysis was conducted on the medical records of 2,840 patients <5 years of age who were hospitalized at Inje University Sanggye Paik Hospital in these time periods. Results: When we compared 2 separate sets of data from before (2005-2006) and after (2011-2012) vaccine introduction, there were statistically significant decreases in the number of patients who were hospitalized for acute gastroenteritis across all of the groups of patients <5 years of age except those <2 months of age. The number of patients with rotavirus gastroenteritis in all age groups declined except for children <2 months of age and those 2-5 months of age. Conclusion: These results show that after the introduction of a rotavirus vaccine in Korea, the incidence of rotavirus gastroenteritis decreased in 6-59-month-old patients hospitalized for acute gastroenteritis.