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Cost-effectiveness analysis of universal varicella vaccination in Turkey using a dynamic transmission model. PLoS One 2019; 14:e0220921. [PMID: 31408505 PMCID: PMC6692038 DOI: 10.1371/journal.pone.0220921] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 07/25/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND In 2013, Turkey introduced one-dose universal varicella vaccination (UVV) at 12 months of age. Inclusion of a second dose is being considered. METHODS We developed a dynamic transmission model to evaluate three vaccination strategies: single dose at 12 months (1D) or second dose at either 18 months (2D-short) or 6 years of age (2D-long). Costs and utilization were age-stratified and separated into inpatient and outpatient costs for varicella and herpes zoster (HZ). We ran the model including and excluding HZ-related costs and impact of exogenous boosting. RESULTS Five years post-introduction of UVV (1D), the projected varicella incidence rate decreases from 1,674 cases pre-vaccine to 80 cases/100,000 person-years. By 25 years, varicella incidence equilibrates at 39, 12, and 16 cases/100,000 person-years for 1D, 2D-short, and 2D-long strategies, respectively, using a highly effective vaccine. With or without including exogenous boosting impact and/or HZ-related costs and health benefits, the 1D strategy is least costly, but 2-dose strategies are cost-effective considering a willingness-to-pay threshold equivalent to the gross domestic product. The model predicted a modest increase in HZ burden during the first 20-30 years, after which time HZ incidence equilibrates at a lower rate than pre-vaccine. CONCLUSIONS Our findings support adding a second varicella vaccine dose in Turkey, as doing so is highly cost-effective across a wide range of assumptions regarding the burden associated with varicella and HZ disease.
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Luan L, Shen X, Qiu J, Jing Y, Zhang J, Wang J, Zhang J, Dong C. Seroprevalence and molecular characteristics of varicella-zoster virus infection in Chinese children. BMC Infect Dis 2019; 19:643. [PMID: 31324226 PMCID: PMC6642589 DOI: 10.1186/s12879-019-4233-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 06/30/2019] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Varicella-zoster virus (VZV) infection in children is an important public health problem in China. We performed the current study to explore the seroprevalence of VZV infection in Chinese children in order to provide more information for improvement of varicella vaccination in China. METHODS Three thousand fourteen children were recruited from Chinese kindergarten students aged from four to six years. Anti-VZV IgG and IgM were assayed using enzyme-linked immunosorbent assay. Both ORF22 and ORF62 of VZV were amplified, sequenced, and analyzed by nested PCR. RESULTS Among 3014 children, 43.9% of boys and 46.3% of girls were vaccinated with varicella vaccine, respectively. The seroprevalence of anti-VZV IgG was 54.4% in the children with varicella vaccination, which was significantly higher than those in unvaccinated children (49.2%) (χ2 = 8.206, P = 0.004). Among of the vaccinated children, the detection rates of VZV IgG antibody increased with age, with 49.4, 50.9 and 58.9% in 4, 5 and 6-year groups, respectively (Trend χ2 = 17.202, P = 0.002). However, there was no difference in anti-VZV IgG detection rates among those unvaccinated children in different age groups (Trend χ2 = 8.681, P = 0.070). In addition, 13 boys and 13 girls were positive for anti-VZV IgM, respectively. Among of them, eight children (0.6%) have received varicella vaccination, which was similar to those in unvaccinated children (1.1%). However, only one ORF22 sequence was isolated from an unvaccinated 5-year boy. Compared to the reference VZV sequences, the nucleotide homology was estimated to be 99.7% with genotype J. CONCLUSIONS Our study indicated that about half of Chinese children aged four to six years have a high risk of VZV infection. It should be helpful for the evaluation on the necessity of varicella immunization in China.
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Affiliation(s)
- Lin Luan
- Suzhou Center for Disease Control and Prevention, 72 Sanxiang Road, Suzhou, 215000, China
| | - Xiaochen Shen
- Gusu Center for Disease Control and Prevention, Suzhou, China
| | - Jing Qiu
- Department of Epidemiology and Statistics, School of Public Health, Jiangsu Key Laboratory and Translational Medicine for Geriatric Disease, Medical College of Soochow University, 199 Renai Road, Suzhou, 215123, Jiangsu, China
- Shanghai Center for Disease Control and Prevention, Shanghai, China
| | - Yang Jing
- Department of Epidemiology and Statistics, School of Public Health, Jiangsu Key Laboratory and Translational Medicine for Geriatric Disease, Medical College of Soochow University, 199 Renai Road, Suzhou, 215123, Jiangsu, China
| | - Jingqi Zhang
- Department of Epidemiology and Statistics, School of Public Health, Jiangsu Key Laboratory and Translational Medicine for Geriatric Disease, Medical College of Soochow University, 199 Renai Road, Suzhou, 215123, Jiangsu, China
| | - Jie Wang
- Department of Epidemiology and Statistics, School of Public Health, Jiangsu Key Laboratory and Translational Medicine for Geriatric Disease, Medical College of Soochow University, 199 Renai Road, Suzhou, 215123, Jiangsu, China
| | - Jun Zhang
- Suzhou Center for Disease Control and Prevention, 72 Sanxiang Road, Suzhou, 215000, China.
| | - Chen Dong
- Department of Epidemiology and Statistics, School of Public Health, Jiangsu Key Laboratory and Translational Medicine for Geriatric Disease, Medical College of Soochow University, 199 Renai Road, Suzhou, 215123, Jiangsu, China.
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Kim J, Kim JE, Bae JM. Incidence of varicella in children in Jeju-do, Korea, 2005-2016: age-period-cohort analysis. Epidemiol Health 2018; 40:e2018054. [PMID: 30428643 PMCID: PMC6302224 DOI: 10.4178/epih.e2018054] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 11/08/2018] [Indexed: 11/09/2022] Open
Abstract
OBJECTIVES Although the nationwide inoculation rate of varicella vaccine was approximately 95% in Korean children recently, the number of notified varicella cases is unexpectedly continuously increasing till now. To suggest some hypotheses regarding this discrepancy, an age-period-cohort (APC) analysis as a descriptive epidemiology study was conducted for children residing in Jeju-do, Korea. METHODS The raw data were obtained from the nationwide database for insurance claim of healthcare fee provided by the National Health Insurance Service, Korea. The selection criteria were children aged 2-13 years who visited any healthcare center due to varicella from 2005 to 2016 while residing in Jeju-do. After calculating the birth cohort-specific crude incidence rates by age and year, the intrinsic estimator method was used to perform the APC analysis. RESULTS As the annual crude incidence rates decreased with increasing age between 2005 and 2016, the age and period effects also decreased. The intrinsic estimator coefficients suggesting the cohort effect shifted from positive to negative in 2011, the starting year of free varicella vaccine program in Jeju-do. CONCLUSIONS The results suggested that inoculated varicella vaccines have preventive effects. However, further studies to evaluate waning immunity would be needed.
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Affiliation(s)
- Jinhee Kim
- Jeju Center for Infection Control, Jeju, Korea
| | - Ji-Eun Kim
- Jeju Center for Infection Control, Jeju, Korea
| | - Jong-Myon Bae
- Department of Preventive Medicine, Jeju National University School of Medicine, Jeju, Korea
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Zhang L, Ma W, Liu Y, Wang Y, Sun X, Hu Y, Deng X, Lu P, Tang F, Wang Z, Zhou M. Analysis of sero-epidemiological characteristics of varicella in healthy children in Jiangsu Province, China. BMC Infect Dis 2018; 18:563. [PMID: 30428851 PMCID: PMC6234534 DOI: 10.1186/s12879-018-3496-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Accepted: 11/01/2018] [Indexed: 01/28/2023] Open
Abstract
Background In recent years, outbreaks of varicella have continued to occur, and the coverage rate of varicella vaccine in Jiangsu Province, China, remains unclear. This study aims to analyse the levels of immune antibody against varicella and obtain a comprehensive understanding of the varicella attenuated live vaccine (VarV) coverage rate in children aged 1–9 years in Jiangsu Province. Methods From June to October 2016, a cross-sectional survey was conducted to collect 3631 serum samples from healthy children aged 1–9 years in Jiangsu Province. The immunoglobulin G (IgG) antibody levels of varicella were detected by enzyme-linked immunosorbent assay (ELISA). Results The VarV coverage rate of healthy children was only 43.1% (95% CI: 41.1–44.7%). The seroprevalence after vaccination with a single dose of VarV was only 57.1%, and the overall seropositivity and geometric antibody titre (GMC) were 43.5% and 225.4 mU/ml, respectively. The seropositivity was significantly higher in girls than in boys (χ2 = 18.82, P < 0.001). The difference in seropositivity between the 5–9 age group and 1–4 age group was statistically significant (χ2 = 84.31, P < 0.001). The difference in seropositivity between different regions was statistically significant, with the highest seropositivity in the northern area, 53.7% (χ2 = 35.64, P < 0.001). The seropositivity in the group receiving one dose of VarV was significantly higher than that of the unvaccinated group (χ2 = 205.16, P < 0.001). Linear regression analysis suggested that the GMC of varicella antibodies wanes with the time since vaccination (F = 65.01, P = 0.002). Conclusion The VarV coverage rate of healthy children in Jiangsu Province was low. Sero-conversion rates were also low after one dose of VarV, and the immune effectiveness of a single dose of VarV was limited. To control the spread of varicella, VarV should be included in the routine immunization program, and strengthened immunization measures for the varicella-susceptible population warrant additional consideration.
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Affiliation(s)
- Lei Zhang
- Department of Epidemiology, School of Public Health, Nanjing Medical University, Nanjing, 211166, Jiangsu Province, China
| | - Wang Ma
- First Affiliated Hospital of Nanjing Medical University, Nanjing, 211166, Jiangsu Province, China
| | - Yuanbao Liu
- Department of Expanded Programme on Immunization, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, 210009, Jiangsu Province, China
| | - Yong Wang
- Department of Epidemiology, School of Public Health, Nanjing Medical University, Nanjing, 211166, Jiangsu Province, China
| | - Xiang Sun
- Department of Expanded Programme on Immunization, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, 210009, Jiangsu Province, China
| | - Ying Hu
- Department of Expanded Programme on Immunization, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, 210009, Jiangsu Province, China
| | - Xiuying Deng
- Department of Expanded Programme on Immunization, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, 210009, Jiangsu Province, China
| | - Peishan Lu
- Department of Expanded Programme on Immunization, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, 210009, Jiangsu Province, China
| | - Fenyang Tang
- Department of Expanded Programme on Immunization, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, 210009, Jiangsu Province, China
| | - Zhiguo Wang
- Department of Expanded Programme on Immunization, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, 210009, Jiangsu Province, China.
| | - Minghao Zhou
- Department of Epidemiology, School of Public Health, Nanjing Medical University, Nanjing, 211166, Jiangsu Province, China. .,Department of Expanded Programme on Immunization, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, 210009, Jiangsu Province, China.
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