OBJECTIVES: The reported incidence rate of varicella infection in Jeju-do is higher compared with the national average. This study aimed to examine varicella vaccination history and evaluate clinical manifestation of varicella cases in Jeju-do.METHODS: Based on the guideline suggested by the Korea Centers for Disease Control and Prevention (KCDC), two epidemic investigations for varicella infection were conducted in the first half of 2017. The history of varicella vaccination was confirmed using the Integrated Control System for Diseases and Health operated by the KCDC.RESULTS: Out of a total of 60 elementary school children as the study subjects, all had been previously vaccinated against varicella. Twenty cases (33%) showed mild clinical manifestations and no complications.CONCLUSIONS: As the government of Jeju-do has supplied a single-labeled vaccine since 2011, there is a need to evaluate the type of vaccination failure such as primary or secondary.
Centers for Disease Control and Prevention (U.S.) ; Chickenpox Vaccine ; Chickenpox ; Child ; Humans ; Immunization ; Incidence ; Jeju-do ; Korea ; Vaccination

OBJECTIVE: To evaluate the cost/benefit of different vaccination strategies related to chickenpox vaccine. METHODS: The direct economic cost and indirect economic cost caused by chickenpox were obtained through questionnaire survey. The epidemic characteristics of chickenpox in Zhejiang province were studied by literature review. Dynamic model was set up by Matlab software based on the parameters of chickenpox, to predict the incidence trends of chickenpox with different immunization strategies (no vaccination, 1-dose vaccination, 2-dose vaccination) in future 40 years (2017-2056). A cost-benefit analysis was conducted, and the sensitivities of the main parameters were analyzed. RESULTS: Through the questionnaire survey of 105 cases, the direct and indirect economic cost per case was 506.84 Yuan and 1045.39 Yuan respectively, with the total of 1552.23 Yuan. During the prediction period (40 years), there would be 7.0908 million cases in strategy 2, which was 59.71% less than strategy 1 (17.5989 million cases). Total vaccination costs in strategy 2 were 2.366 billion Yuan, with a total economic gain of 33.741 billion Yuan and benefit/cost ratio (BCR) of 14.26:1. If strategy 3 was adopted, 2.7249 million chickenpox cases would occur, with a decrease of 84.52% compared with strategy 1. Total vaccination costs in strategy 3 was 4.495 billion Yuan, with a total economic gain of 44.309 billion Yuan and BCR of 9.86:1. Analysis showed that the vaccine price was the most sensitive variable, followed by the incidence of chickenpox in the absence of vaccine. CONCLUSIONS In Zhejiang province, one-dose strategy and two-dose strategy were both cost effective. It is suggested that the chickenpox vaccination should be included in the immunization program in Zhejiang province.
Chickenpox ; prevention & control ; Chickenpox Vaccine ; Cost-Benefit Analysis ; Humans ; Immunization Programs ; economics ; methods ; Vaccination ; economics

OBJECTIVES: The reported incidence rate of varicella infection in Jeju-do is higher compared with the national average. This study aimed to examine varicella vaccination history and evaluate clinical manifestation of varicella cases in Jeju-do. METHODS: Based on the guideline suggested by the Korea Centers for Disease Control and Prevention (KCDC), two epidemic investigations for varicella infection were conducted in the first half of 2017. The history of varicella vaccination was confirmed using the Integrated Control System for Diseases and Health operated by the KCDC. RESULTS: Out of a total of 60 elementary school children as the study subjects, all had been previously vaccinated against varicella. Twenty cases (33%) showed mild clinical manifestations and no complications. CONCLUSIONS: As the government of Jeju-do has supplied a single-labeled vaccine since 2011, there is a need to evaluate the type of vaccination failure such as primary or secondary.
Centers for Disease Control and Prevention (U.S.) ; Chickenpox Vaccine ; Chickenpox* ; Child* ; Humans ; Immunization ; Incidence ; Jeju-do ; Korea* ; Vaccination*

Objective: To investigate the breakthrough rate and antibody level of children vaccinated two doses varicella vaccine in Tianjin city, and to compare them with those vaccinated one dose. Methods: A total of 1 112 children who were vaccinated two doses varicella vaccine were selected as the experimental group. According to the same street and township, children who had received only one dose within one year of age difference, and whose first injection time was less than one month from the first dose of varicella vaccine in the experimental group were selected as the control group. A three-year prospective observation was conducted on the incidence of varicella in the two groups. 108 pairs of children in the two groups were selected to collect antivaricella serum in the first to third year. The rate of breakthrough cases, antibody level and antibody positive rate were compared by χ² test, t-test and variance analysis between and within the two groups in three years. Results: The cumulative breakthrough rate of the experimental group was 0.54%(6/1 112), which was lower than that of the control group 3.96% (44/1 112, χ²=29.544, P<0.001). The GMC level of antibody in the experimental group decreased year by year (F=18.291, P<0.001), and the GMC level in the control group also decreased year by year (F=91.383, P<0.001). There was significant difference in GMC level between the two groups (P<0.001). The difference of antibody positive rate in the experimental group was statistically significant in three years (χ²=11.107, P<0.01), there was significant difference in the positive rate between the first year and third year (P<0.01), there was no significant difference in the positive rate of the control group in three years (χ²=3.351, P>0.05). The positive rate of the experimental group was higher than that of the control group (P<0.001). Conclusion: Two doses varicella vaccine can significantly improve the antibody level and positive rate, but it still shows a downward trend with the extension of time. It is necessary to consider strengthening immunization according to the actual situation.
Antibodies, Viral ; Chickenpox/prevention & control* ; Chickenpox Vaccine ; Child ; Herpesvirus 3, Human ; Humans ; Infant ; Prospective Studies ; Vaccination

OBJECTIVETo study the epidemiological impact of varicella vaccine vaccination on kindergartens and school children in Beijing.

METHODSAccording to "China Information System for Diseases Control and Prevention", the reported clinical diagnosis varicella cases were tracked in kindergartens, primary and secondary schools whose onset date were from 2008 to 2010. Epidemiological survey was conducted and epidemiological features were analyzed.

RESULTSA total of 21 474 varicella cases were investigated: 55.3% (11 883 cases) had been vaccinated by varicella vaccine. Of cases with definite immunization history, interval between vaccination date and onset date were from 30 days to 1 year accounted for 3.4% (286/8510), 1 to 3 years accounted for 18.2% (1551/8510), 3 to 5 years accounted for 28.6% (2431/8510), 5 to 10 years accounted for 34.3% (2916/8510) (left-closed right-open interval); The peak age of onset was 4 years old in cases without immunization history, which was 6 years old in cases with immunization history; The proportion of cases with immunization history (≥ 30 days) had increased from 42.4% (2862/6754) in 2008 to 56.3% (4327/7679) in 2010. The cases with no fever had a higher proportion (54.9%, 6413/11 679) of immunization history (≥ 30 days) than cases with fever (47.7%, 4533/9500) (P < 0.01); The cases with rashes less than 50 had a higher proportion (57.4%, 8045/14 020) of immunization history (≥ 30 days) than cases with rashes more than 50 (40.2%, 2902/7216) (P < 0.01).

CONCLUSIONVaricella vaccine delays the peak age of onset, alleviates the symptoms. The current immunization strategy can not block varicella spread in kindergartens, primary and secondary schools.

Adolescent ; Chickenpox ; epidemiology ; prevention & control ; Chickenpox Vaccine ; Child ; Child, Preschool ; China ; epidemiology ; Female ; Humans ; Male ; Schools ; Schools, Nursery

Objective: To analyze the differences between adults and children in the epidemic characteristics and clinical manifestations of chickenpox and provide a reference for the prevention strategy adjustment of chickenpox. Methods: The incidence data of chickenpox surveillance in Shandong Province from January 2019 to December 2021 were collected. Descriptive epidemiological methods were used to analyze the distribution of cases, and the chi-square test was used to compare the differences in epidemiological characteristics and clinical manifestations of varicella cases between adults and children. Results: A total of 66 182 cases of chickenpox were reported from 2019 to 2021, including 24 085 cases of adults chickenpox, the male to female sex ratio was 1∶1 (12 032∶12 053), basically the same for men and women, and 42 097 cases of children chickenpox, with a gender ratio of 1.4∶1, the male to female ratio was 1.4∶1 (24 699∶17 398). Fever in chickenpox cases was mainly low and moderate, but the proportion of moderate fever with temperature between 38.1 and 39.0 ℃ in children cases (35.0%,14 744/42 097) was significantly higher than that in adults (32.0%,7 696/24 085). The number of herpes in chickenpox cases was mainly less than 50, but the proportion of severe cases with 100-200 herpes in children was higher than that in adults. The incidence rate of complications was 1.4% (333/24 085) in adults chickenpox, the incidence rate of complications was 1.7% (731/42 097) in children chickenpox. The incidence of encephalitis and pneumonia in children was higher than in adults, and the difference was statistically significant (P<0.05). The proportion of chickenpox cases was mainly outpatient, but the hospitalization rate of children cases was 14.4% (6 049/42 097), higher than that of adults, which was 10.7% (2 585/24 085). Conclusions: There were differences between adult chickenpox and child chickenpox in terms of epidemic and clinical manifestations; the symptoms of child chickenpox were more serious than adult chickenpox. However, the adult chickenpox population is generally susceptible and lacks immune strategy protection, which calls for more attention.
Child ; Humans ; Adult ; Male ; Female ; Infant ; Chickenpox/prevention & control* ; Hospitalization ; Incidence ; Pneumonia/epidemiology* ; Epidemics ; Fever/epidemiology* ; Chickenpox Vaccine

Chickenpox ; prevention & control ; China ; Disease Outbreaks ; prevention & control ; Humans ; Schools ; Vaccination ; statistics & numerical data

OBJECTIVEforecast the epidemic trend and to evaluate the effect of outbreak control measures by investigation of a varicella outbreak event with a discrete time delay SEIR model.

METHODSA discrete time delay model was formulated by discretization method based on a continuous SEIR model with the consideration of the time delay effect on latent period and communicable period. The epidemic trend forecast was carried out based on the number of expected cases. The theoretical effect evaluation was assessed by comparing the results from different emergency control measures.

RESULTSWithout any control measures, the theoretical attack rate was 30.16% (504/1671). The course of the epidemic lasted for 4 months and the peak epidemic time was 78 days after the onset of the first case. 'Generation' phenomenon had been observed in the course of the epidemic with the interval of two weeks. The actual number of cases was decreased by 89.48% (451/504) compared with the number of expected cases under no control measure scenario. With the rigorous quarantine measure for all cases on their onset day, when the measure was conducted on 0, 14, 28, 42 days after the onset of the first case, the total numbers of expected cases were 22, 59, 127 and 220 respectively. With the quarantine measure conducted on 14 days after the onset of the first case, when the proportion of quarantine was 30%, 50%, 70%, 90%, the total number of expected cases were 485, 457, 386 and 169, respectively. With the emergent vaccination for all persons, when the measure was conducted on 0, 14, 28, 42 days after the onset of the first case, the total numbers of expected cases were 7, 26, 81 and 202 respectively. With the emergent vaccination conducted on 14 days after the onset of the first case, when the immunization coverage rate was 30%, 50%, 70%, 90%, the total numbers of expected cases were 354, 246, 127 and 40, respectively.

CONCLUSIONThe number of expected cases can be regarded as the reference to evaluate the effect of control measures. The simulation results suggest that it will get more benefits to conduct control measures earlier in varicella outbreak events, and the effect of emergent vaccination is better than that of quarantine measure under the same conditions.

Chickenpox ; epidemiology ; prevention & control ; Communicable Disease Control ; methods ; Disease Outbreaks ; prevention & control ; Humans ; Incidence ; Models, Theoretical

Chickenpox ; prevention & control ; Chickenpox Vaccine ; therapeutic use ; Child ; China ; epidemiology ; Communicable Disease Control ; methods ; Disease Outbreaks ; prevention & control ; Female ; Humans ; Male ; Schools ; Students

With the determination of the whole genome sequence of varicella-zoster virus (VZV) virus, the successful breakthrough of infectious cloning technology of VZV, and the emergence of effective preventive vaccines, which have been proven to be effective and safe, varicella has become a disease preventable by specific immunity. This article will review the genomic structure, epidemiological characteristics, and research application progress of varicella vaccine and herpes zoster vaccine of varicella zoster virus to provide reference for primary prevention of the disease.
Humans ; Herpesvirus 3, Human/genetics* ; Herpes Zoster/prevention & control* ; Herpes Zoster Vaccine ; Chickenpox Vaccine ; Genomics