• The Journal of Korean Society of Virology
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• v.30 no.1
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• pp.11-18
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• 2000

Since $Hantavax^{TM}$, formalin inactivated Hantaan virus vaccine (10,240 ELISA units/ml), has been developed in 1990 to prevent against haemorrhagic fever with renal syndrome (HFRS) caused by Hantaan or Seoul virus, it has been commercially available in Korea. Twenty-one healthy people were booster shot once and twice after primary basic vaccination with $Hantavax^{TM}$. Seroconversion rates were measured by immunofluorescent antibody technique (IFAT), enzyme-linked immunosorbent assay (ELISA), high density composite particle agglutination (HDPA), and plaque reduction neutralization test (PRNT). Seroconversion rates of 21 vaccinees at one year after primary basic vaccination were 52.3%, 95.2%, 0.0%, 47.6%, and 28.6%, and 13 vaccinees at one month after 1st booster vaccination were 100%, 100%, 30.7%, 100% and 100% by IFAT, ELISA (IgG, IgM), HDPA and PRNT, respectively. Seroconversion rates declined slightly by twenty months, and they were 84.6%, 92.3%, 0.0%, 84.6% and 69.2% by IFAT, ELISA (IgG, IgM), HDPA and PRNT, respectively. Seroconversion rates of 9 vaccinees at three months after 2nd booster vaccination were 100%, 100%, 0.0%, 100%, and 88.9%, and 16 vaccinees at one year after the 2nd booster vaccination were 87.5%, 93.8%, 0.0%, 87.5% and 81.3% by IFAT, ELISA (IgG, IgM), HDPA and PRNT, respectively. Based on the above result $Hantavax^{TM}$ has proved a vigorous anamnestic response after the 1st and the 2nd booster vaccination and has persisted higher fluorescence, agglutination and neutralizing antibody titers in vaccinees.

• Journal of Preventive Medicine and Public Health
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• v.42 no.2
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• pp.104-108
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• 2009

Objectives : To increase the booster vaccination rate, the Korean government legislated a measles vaccination for elementary school students in 2001, requiring parents to submit a certificate of vaccination upon the admission of the students to elementary school. The purpose of this study was to evaluate the validity of measles vaccination certificates which were issued to parents. Methods : Using questionnaire survey data of 890 general practitioners and 9,235 parents in 2005, we investigated the evidence for booster vaccination certificates of measles. Results : In the survey of general practitioners, 59.5% of the certificates depended on the medical records of clinic, 13.5% was immunization booklets, 23.7% was reimmunizations, 1.9% was confirmation of record of other clinics, and 1.4% was parents statements or requests without evidence. In the survey of parents, 36.2% of the certificates depended on the medical records of clinic, 43.4% was immunization booklets, 18.0% was reimmunizations, and 2.4% was parents statements or requests without evidence. Conclusions : Our findings show that a majority of the booster vaccination certificates of measles was issued on the basis of documented vaccinations and it means that the implementation of the law requiring the submission of elementary school students' vaccination certificates has been very successful in Korea.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.4
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• pp.559-563
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• 2001

The effects of feeding a mannan oligosaccharide (Bio-Mos) from 0 to 3 g/kg diet and vaccination program on 1- to 35-day performance (growth and feed efficiency), metabolizable energy, nitrogen utilization and carcass composition of meat chickens were investigated. A general vaccination program was used against IB, IBD and ND with half of the birds per diet receiving a booster dose of IB and ND vaccines at 12 days of age. Dietary supplementation of Bio-Mos (BM) did not influence body weight gain, feed efficiency and nutrient utilization. The highest dietary BM (3 versus 1.5 or 0 g/kg) increased carcass abdominal fat and reduced the proportion of drumstick in the carcass of meat chickens. The booster dose reduced the performance of birds. It was concluded that the addition of BM to the diet of chickens did not significantly influence the performance and nutrient utilization of meat chickens.

• Clinical and Experimental Pediatrics
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• v.54 no.4
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• pp.163-168
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• 2011

Purpose: The purpose of this study was to evaluate the immune response to serotype 19A in children aged 12-23 months after immunization of the 19F containing 7-valent pneumococcal conjugate vaccine (PCV7). Methods: Blood samples from a total of 45 subjects (age 12-23 months) were included in the study. Subjects were categorized according to immunization status into three groups as follows: 18 subjects with 3 primary doses and 1 booster dose of PCV7 (booster group), 21 subjects with 3 primary doses before 12 months of age (primary group), and 6 subjects with no vaccination history of PCV7 (control group). An ELISA and opsonophagocytic killing assay (OPKA) was done to evaluate the immune responses against serotypes 19F and 19A. Results: According to the ELISA, all subjects had antibody titers ${\geq}0.35{\mu}g/mL$ for serotypes 19F and 19A in the booster and primary group and 83.0% and 66.7% in the control group, respectively. According to the OPKA, subjects with opsonic activity (${\geq}20$) against serotypes 19F and 19A were 100% and 61.1% of the subjects in the booster group and 66.7% and 19.0% in the primary group, respectively. No subjects in the control group had opsonic antibodies against both serotypes. Conclusion: In conclusion, in children 12-23 months age who were previously vaccinated with PCV7, a cross-reactive immune response is elicited against serotype 19A after a primary series of 3 doses in a small proportion of subjects, and this response is amplified after booster vaccination.

• Pediatric Infection and Vaccine
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• v.4 no.2
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• pp.240-256
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• 1997

Purpose: To evaluate the hepatitis B vaccination program which has been conducted since 1980, Korea. Methods: This study was carry out self reported questionnaire and serologic test covering 2,072 elementary school students who were born between 1980 and 1987, selected by cluster sampling. The HBV serologic markers (HBsAg, Anti-HBs and Anti-HBc) were tested by radioimmunoassay (RIA). The contents of questionnaire include demographic data of students and parents, vaccination status, vaccination frequency, vaccination age, past history of mother's HBV test. Results: 1) The HBsAg positive rates by sex showed 3.7% for male and 2.7% for female, representing an average rate of 3.4%. The HBsAg positive rates by age group showed 5.6% for 13 years and l.5% for 6 years, representing a tendency of lowering rate as ages being younger. 2) The pre-natal HBV test rate was 10.2%, while post-natal HBV test rate was 42.5%. The test showed that the parents' educational level being higher than others, the pre- and post-natal HBV test showed higher rates. In case the fathers occupation being office worker, the post-natal HBV test showed a higher rate compared with other occupation. 3) Overall vaccination rate was 82.6%, complete vaccination rate 69.8%, booster injection rate 42.8%. The vaccination rate, complete vaccination rate and booster injection rate increased as the age being younger. If the educational level of parents were higher, the vaccination rate, complete vaccination rate and booster injection rate showed higher rates. Younger students showed younger vaccination age, and higher educational background of family showed younger vaccination ages. 4. With regard to positive rate of HBV markers by vaccination age, HBsAg and Anti-HBc positive rate showed higher degrees in the following order; preschool age (1-6 years), school age (6-13 years) and infancy (0-1 year). Anti-HBs positive rate was increased as the frequency of vaccination increased. Five years after initial complete vaccination, minimum protective rate was lowest, 69.6%.

• IMMUNE NETWORK
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• v.22 no.4
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• pp.31.1-31.3
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• 2022

• Genomics & Informatics
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• v.21 no.4
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• pp.50.1-50.9
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• 2023

Vaccine development is one of the key efforts to control the spread of coronavirus disease 2019 (COVID-19). However, it has become apparent that the immunity acquired through vaccination is not permanent, known as the waning effect. Therefore, monitoring the proportion of the population with immunity is essential to improve the forecasting of future waves of the pandemic. Despite this, the impact of the waning effect on forecasting accuracies has not been extensively studied. We proposed a method for the estimation of the effective immunity (EI) rate which represents the waning effect by integrating the second and booster doses of COVID-19 vaccines. The EI rate, with different periods to the onset of the waning effect, was incorporated into three statistical models and two machine learning models. Stringency Index, omicron variant BA.5 rate (BA.5 rate), booster shot rate (BSR), and the EI rate were used as covariates and the best covariate combination was selected using prediction error. Among the prediction results, Generalized Additive Model showed the best improvement (decreasing 86% test error) with the EI rate. Furthermore, we confirmed that South Korea's decision to recommend booster shots after 90 days is reasonable since the waning effect onsets 90 days after the last dose of vaccine which improves the prediction of confirmed cases and deaths. Substituting BSR with EI rate in statistical models not only results in better predictions but also makes it possible to forecast a potential wave and help the local community react proactively to a rapid increase in confirmed cases.

• Pediatric Infection and Vaccine
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• v.8 no.2
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• pp.150-159
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• 2001

Purpose : We need to reconsider booster vaccination schedule of Japanese encephalitis vaccination. To do that we evaluate the long-term immunogenicity and the incidence of adverse events with inactivated mouse brain derived Nakayama Japanese encephalitis vaccine. Methods : We tested neutalizing antibody for 311 elementary school students by plaque reduction neutralizing test(PRNT) at USAMC-AFRIMS(United States Armed Forces Research Institute of Medical Science/Department of Virology). We evaluated vaccine related adverse events by spontaneous reporting prospectively among 15,487 vaccinees who were vaccinated at public health center and 2,277 elementary school students who were immunized previously by a questionnaire and school health record. Results : According to the time interval from the last booster injection of 311 children, PRNT antibody titers gradually decreased as the interval increased; 239 mIU/mL, 188 mIU/mL, 134 mIU/mL, 49 mIU/mL each at 6, 18, 30, 42 months after the last booster injection. The seropositivity rates were 98%, 99%, 95.6%, 71.4% each at 6, 18, 30, 42 months after the last booster injection. There were 21(0.13%) cases with systemic reactions among 15,487 vaccinees who had visited the hospital by prospective passive reporting system at public health center. According to the questionnaires and school health records in elementary school students, local induration and pain were 17.4% and 14.8%, respectively. Systemic reactions including fever, vomiting, rash were reported in few cases. Conclusion : Biannual booster vaccination that has been recommended so far should not be necessary. Surveillance for adverse events with inactivated mouse brain derived Nakayama vaccine should be strengthened to better assess the number of cases and reactions associated with immunization.

• Clinical and Experimental Pediatrics
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• v.51 no.11
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• pp.1185-1190
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• 2008

Purpose : This study was undertaken to evaluate the immunogenicity and reactogenicity of Td booster immunization in early preadolescents of Korea. Methods : Healthy preadolescents, who had been vaccinated with 4 or 5 doses of DTaP vaccines until 6 years old age, were enrolled in this study from August 2006 to April 2007. Diphtheria and tetanus anti-toxoid antibodies in sera were measured by ELISA just before vaccination and 4 weeks after vaccination to evaluate immunogenicity. Local and systemic adverse reactions observed for 4 weeks after vaccination to access reactogenicity. Results : 183 preadolescents were enrolled and mean age was $11.40{\pm}0.51$ years old. All subjects achieved seroprotective diphtheria and tetanus anti-toxoid antibodies (titers ${\geq}0.1IU/mL$) after Td booster vaccination. Among 183 vaccinees, 73.8% showed local adverse reactions and 37.2% systemic adverse reactions. Pain at injection site (66.1%) was the most common local reaction, and the most commonly shown systemic reaction was myalgia (17.5%). The adverse reactions were spontaneously relieved within three days after vaccination. Conclusion : Td vaccine in this study was high immunogenic and showed an acceptable tolerance in Korean preadolescents. Td booster vaccination at 11-12 years old is the most effective method to increase compliance of the vaccination and to decrease the incidence of diphtheria and tetanus.

• Pediatric Infection and Vaccine
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• v.4 no.1
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• pp.116-125
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• 1997

Purpose : Studies on the duration of immune response against Japanese encephalitis virus from recipients with JE vaccine (Nakayama-NIH strain) in Korea. Methods : To determinate the immune response and the duration of antibody against JE vaccine, 213 students were examined since 1994 using hemmaglutination inhibition test and plaque reduction neutralization test (PRNT). Results : 24 months after the first vaccination, haemmaglutination inhibition and neutralizing antibody maintained from the recipients 63.4% (>1:20) and 100% (>1:20), respectively. In April 1996, one dose booster to the same recipients those who were vaccinated in 1994, the GMT antibody for HI and PRNT titer were both increased from 1:11.6 to 1:13.2 and 1:275.7 to 1:348.1, respectively, after 6 months booster (after 30 months from the initial vaccination). This results showed that the antibody from the active immunity could be maintained more than 12 months after the initial vaccination. On the basis of these results, inactivated killed JE vaccine (Nakayama-NIH strain) using for preventing against JE purpose seems to produce antibody enough to protect against JE at present. Conclusions : Along with the results of this study demonstrating duration of antibody, the active immunization could be maintained as long as by initial vaccination of 2 doses, a single dose of booster vaccination made during a period of 1 month to 12 months and the successive booster vaccination by 2 or 3 year intervals. However, the immunization schedule should be concerned with both epidemiology of disease and the immune response of vaccinated individuals.