1
|
Liu F, Li Z, Wang H, Cao Y, Zhang N, Wang F, Wei R, Zhang J, Zhao Y. Effectiveness of the varicella vaccine in the real world, a matched case-control study. Vaccine 2024; 42:3968-3973. [PMID: 38734496 DOI: 10.1016/j.vaccine.2024.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 04/28/2024] [Accepted: 05/06/2024] [Indexed: 05/13/2024]
Abstract
BACKGROUND Universal varicella vaccination has been introduced in many countries, but there are a number of important differences in their vaccination strategies. It is essential to establish a vaccination program that can maximize the benefits of varicella vaccine, but there is a lack of comprehensive research on the effectiveness of varicella vaccine in different vaccination status. METHODS Using data from population-based surveillance platforms we conducted a 1:2 matched case-control study. The cases were clinically diagnosed varicella with onset from 2017 to 2021, 1-14 years old in Chaoyang District, Beijing. The controls were matched according to date of birth (±1 month), sex and residence. The vaccination data of the subjects were obtained from the Childhood Immunization Information Management System in Beijing. Using conditional logistic regression models with or without interaction terms, we evaluated the effectiveness of varicella vaccine in different vaccination status. RESULTS A total of 2528 cases and 5056 controls were enrolled. This study found that whether the time since last vaccination was adjusted had a substantial effect on the comparing vaccine effectiveness (VE) between subgroups. After adjustment for the time since last vaccination, 1) the incremental VE of 2-dose was 49.6 % (95 % Confidence Interval [CI], 38.8-58.6) compared with 1-dose (93.9 % vs. 88.0 %); 2) Among children who received one dose, the risk of chickenpox in children vaccinated at 18-23 months was 1.382 (95 %CI, 1.084-1.762) times that in children vaccinated at 12-17 months. 3) the VE with less than one, two, and three year intervals is higher than that with six-year-intervals (P < 0.05), respectively. CONCLUSIONS When comparing VE between subgroups of different vaccination status, the time since last vaccination should be adjusted. The first dose of varicella vaccine should be given as early as the second year of life, and the second dose can improve vaccine effectiveness.
Collapse
Affiliation(s)
- Fang Liu
- Beijing Chaoyang District Center for Disease Control and Prevention, Beijing, China.
| | - Zhen Li
- Beijing Chaoyang District Center for Disease Control and Prevention, Beijing, China
| | - Hongyu Wang
- Haidian District Maternal and Child Health Care Hospital, Beijing, China
| | - Yang Cao
- Beijing Chaoyang District Center for Disease Control and Prevention, Beijing, China
| | - Nan Zhang
- Beijing Chaoyang District Center for Disease Control and Prevention, Beijing, China
| | - Fang Wang
- Beijing Chaoyang District Center for Disease Control and Prevention, Beijing, China
| | - Rui Wei
- Beijing Chaoyang District Center for Disease Control and Prevention, Beijing, China
| | - Jian Zhang
- Beijing Chaoyang District Center for Disease Control and Prevention, Beijing, China
| | - Yuqian Zhao
- Beijing Chaoyang District Center for Disease Control and Prevention, Beijing, China
| |
Collapse
|
2
|
Sakaue T, Sugawara T, Mukasa K, Nohara M. Varicella outbreak at nursery school under routine immunization in Japan in 2017 and 2018 and vaccine effectiveness. Vaccine 2024; 42:2637-2645. [PMID: 38480103 DOI: 10.1016/j.vaccine.2024.02.075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 02/19/2024] [Accepted: 02/24/2024] [Indexed: 04/06/2024]
Abstract
BACKGROUND In Japan, routine administration to one-year-old children of two-dose immunization for varicella was introduced in October 2014. Object The object of this study was to report outbreaks of varicella under routine immunization at a nursery school and in its surrounding area using data of surrounding areas from the (Nursery) School Absenteeism Surveillance System. Then, we measured the effectiveness of routine two-dose immunization for varicella to onset. We tentatively assessed its severity in a nursery school. METHOD The study period extended from April 2017 through March 2018. The study area comprised Nursery school B and other nursery schools, and elementary and junior high schools in City A. Subjects in Nursery school B were 120 children. We analyzed vaccine effectiveness (VE) as an observational study and assessed severity using Fisher's exact test. We also assessed VE for severity using linear regression. Severity was defined as the length of nursery school absence attributable to varicella infection. RESULTS During the one month preceding a period of two weeks before the initial case at Nursery school B, there were 16 cases of varicella infection in nursery schools, 45 cases in elementary schools, and one case in junior high schools in City A. For children who had received one vaccine dose or more, VE was 48.1% for all ages and 49.2% among children three years old and older. No significant VE against infection was found. Vaccination using one dose or more can reduce severity significantly. DISCUSSION AND CONCLUSION Because many nursery school children who had received two doses of vaccine were infected, VE was estimated as low in the nursery school and not significant. Although VE for severity with more than one dose was confirmed, a second dose might not reduce severity compared to one dose.
Collapse
Affiliation(s)
| | - Tamie Sugawara
- National Institute of Infectious Diseases, Tokyo, Japan.
| | - Kyoko Mukasa
- Department of Social Welfare, Faculty of Humanities and Social Science, Showa Women's University, Tokyo, Japan
| | | |
Collapse
|
3
|
Ishiguro C, Mimura W, Uemura Y, Maeda M, Murata F, Fukuda H. Multiregional Population-Based Cohort Study for Evaluation of the Association Between Herpes Zoster and mRNA Vaccinations for Severe Acute Respiratory Syndrome Coronavirus-2: The VENUS Study. Open Forum Infect Dis 2023; 10:ofad274. [PMID: 37404955 PMCID: PMC10316690 DOI: 10.1093/ofid/ofad274] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 05/17/2023] [Indexed: 07/06/2023] Open
Abstract
Background This study was performed to assess the increased risk of herpes zoster (HZ) associated with mRNA vaccines for coronavirus disease 2019. Methods This population-based cohort study was conducted in 4 municipalities in Japan. Individuals covered under public health insurance systems without a history of HZ were followed from October 1, 2020 to November 30, 2021. Incidence rates of HZ within 28 days of BNT162b2 or mRNA-1273 vaccination were compared. Adjusted incidence rate ratios (IRR) and 95% confidence intervals (CI) were estimated using a Poisson regression model, including vaccination status as a time-dependent covariate. Subgroup analyses by sex, age, and municipality were also conducted. Results A total of 339 548 individuals (median age, 74 years) were identified. During follow up, 296 242 individuals (87.2%) completed the primary series, among whom 289 213 and 7019 individuals received homologous BNT162b2 and mRNA-1273 vaccines, respectively. The adjusted IRRs of the first and second BNT162b2 vaccinations were 1.05 (95% CI, 0.84-1.32) and 1.09 (95% CI, 0.90-1.32), respectively. No cases of HZ were observed after mRNA-1273 vaccination. In subgroup analysis, the adjusted IRR of the second BNT162b2 vaccination was 2.94 (95% CI, 1.41-6.13) in individuals aged <50 years old. Conclusions No increased risk of HZ was found after BNT162b2 vaccination in the overall study population. However, an increased risk was observed in the younger subgroup.
Collapse
Affiliation(s)
- Chieko Ishiguro
- Correspondence: Chieko Ishiguro, MPH, PhD, Section of Clinical Epidemiology, Department of Data Science, Center for Clinical Sciences, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo 162-8655, Japan (); Wataru Mimura, PhD, Section of Clinical Epidemiology, Department of Data Science, Center for Clinical Sciences, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo 162-8655, Japan ()
| | - Wataru Mimura
- Correspondence: Chieko Ishiguro, MPH, PhD, Section of Clinical Epidemiology, Department of Data Science, Center for Clinical Sciences, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo 162-8655, Japan (); Wataru Mimura, PhD, Section of Clinical Epidemiology, Department of Data Science, Center for Clinical Sciences, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo 162-8655, Japan ()
| | - Yukari Uemura
- Section of Biostatistics, Department of Data Science, Center for Clinical Sciences, National Center for Global Health and Medicine, Tokyo, Japan
| | - Megumi Maeda
- Department of Health Care Administration and Management, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan
| | - Fumiko Murata
- Department of Health Care Administration and Management, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan
| | | |
Collapse
|
4
|
Ishimaru S, Michihata N, Kawamura Y, Uda K, Matsui H, Fushimi K, Yasunaga H, Yoshikawa T. Trend in the Numbers of Hospitalized Patients With Varicella, Herpes Zoster, and Ischemic Stroke in Japanese Individuals <20 Years of Age Before and After Implementation of Universal Varicella Vaccination. Pediatr Infect Dis J 2023:00006454-990000000-00395. [PMID: 36996309 DOI: 10.1097/inf.0000000000003907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/01/2023]
Abstract
Several studies have shown an association between varicella-zoster virus infection and ischemic stroke. We analyzed the trends in the numbers of patients with varicella, herpes zoster and ischemic stroke before and after the universal vaccination program using a Japanese database of hospitalized patients. The number of patients with varicella decreased but those of herpes zoster and ischemic stroke did not change.
Collapse
Affiliation(s)
- Soichiro Ishimaru
- From the Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Japan
| | - Nobuaki Michihata
- Department of Health Services Research, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Yoshiki Kawamura
- From the Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Japan
| | - Kazuaki Uda
- Health Services Research and Development Center, University of Tsukuba, Tsukuba, Japan
| | - Hiroki Matsui
- Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo, Tokyo, Japan
| | - Kiyohide Fushimi
- Department of Health Policy and Informatics, Tokyo Medical and Dental University Graduate School of Medicine, Tokyo, Japan
| | - Hideo Yasunaga
- Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo, Tokyo, Japan
| | - Tetsushi Yoshikawa
- From the Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Japan
| |
Collapse
|
5
|
Higashimoto Y, Hattori F, Kawamura Y, Kozawa K, Hamano A, Kato M, Kato S, Hosokawa A, Enya Y, Ihira M, Yoshikawa T. Analysis of the reliability of rapid diagnostic tests for varicella, including breakthrough cases. J Med Virol 2023; 95:e28569. [PMID: 36762573 DOI: 10.1002/jmv.28569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 01/28/2023] [Accepted: 02/04/2023] [Indexed: 02/11/2023]
Abstract
In the era of universal varicella vaccination, diagnosis of varicella is challenging, especially for breakthrough cases. We sought to clarify the reliability of direct varicella-zoster virus (VZV) loop-mediated isothermal amplification (LAMP) and DermaQuick® VZV using the immunochromatography technique as rapid diagnostic tests for varicella. In addition, the usefulness of saliva as a sample type for direct LAMP was investigated. Among the 46 enrolled patients with suspected VZV infection, 31 patients (67.3%) were positive for the nucleic acid test based on real-time PCR from skin swab samples. Direct LAMP of skin swabs was positive in 29 (63.0%) of 46 patients. DermaQuick® VZV was positive in 25 (54.3%) of 46 patients. VZV DNA was detected in only 48.4% of oral swabs with the direct LAMP method. With real-time polymerase chain reaction (PCR) as the standard for diagnosing varicella, the sensitivity and specificity of DermaQuick® VZV were 80.7% and 100%, respectively. The sensitivity and specificity of direct LAMP from skin swabs were 93.6% and 100%, respectively. The sensitivity and specificity of real-time PCR for DNA extracted from oral swabs were 74.2% and 93.3%, respectively. Thus, oral swab samples are not suitable for breakthrough varicella diagnosis. Although DermaQuick® VZV is considered the most convenient point-of-care test for varicella, its sensitivity and specificity were lower than those of direct VZV LAMP.
Collapse
Affiliation(s)
- Yuki Higashimoto
- Department of Cellular and Molecular Biology, Fujita Health University School of Medical Sciences, Toyoake, Aichi, Japan
| | - Fumihiko Hattori
- Department of Pediatrics, Kariya Toyota General Hospital, Kariya, Aichi, Japan
| | - Yoshiki Kawamura
- Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
| | - Kei Kozawa
- Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
| | - Aoi Hamano
- Department of Cellular and Molecular Biology, Fujita Health University School of Medical Sciences, Toyoake, Aichi, Japan
| | - Mizuki Kato
- Department of Cellular and Molecular Biology, Fujita Health University School of Medical Sciences, Toyoake, Aichi, Japan
| | - Sayaka Kato
- Department of Cellular and Molecular Biology, Fujita Health University School of Medical Sciences, Toyoake, Aichi, Japan
| | - Asuka Hosokawa
- Department of Cellular and Molecular Biology, Fujita Health University School of Medical Sciences, Toyoake, Aichi, Japan
| | - Yasuko Enya
- Department of Clinical Science for Biological Monitoring, Fujita Health University School of Medical Sciences, Toyoake, Aichi, Japan
| | - Masaru Ihira
- Department of Clinical Science for Biological Monitoring, Fujita Health University School of Medical Sciences, Toyoake, Aichi, Japan
| | - Tetsushi Yoshikawa
- Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
| |
Collapse
|
6
|
Yamaguchi M, Tetsuka N, Okumura T, Haruta K, Suzuki T, Torii Y, Kawada JI, Ito Y. Post-exposure prophylaxis to prevent varicella in immunocompromised children. Infect Prev Pract 2022; 4:100242. [PMID: 36120112 PMCID: PMC9471438 DOI: 10.1016/j.infpip.2022.100242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 08/22/2022] [Indexed: 12/02/2022] Open
Abstract
Background Varicella-zoster virus (VZV) infection can cause life-threatening events in immunocompromised patients. Post-exposure prophylaxis (PEP) is required to prevent secondary VZV infection. Limited evidence is available for the use of acyclovir (ACV)/valacyclovir (VCV) as PEP. Methods Herein, we retrospectively analyzed immunocompromised paediatric patients with significant exposure to VZV. Patients administered PEP were categorized into four groups: 1) ACV/VCV group; 2) intravenous immunoglobulin (IVIG) group; 3) ACV/VCV/IVIG group; 4) vaccine group. Results Among 69 exposure events, 107 patients were administered PEP (91, ACV/VCV; 16, ACV/VCV/IVIG) and 10 patients did not receive PEP (non-PEP group). The index case was diagnosed based on clinical symptoms in 55 cases (79.7%). Fourteen cases (20.3%) were confirmed using direct virological diagnostic procedures. In the PEP group, only 2 patients (2.2%) developed secondary VZV infections. Additionally, 2 patients in the non-PEP group (20.0%) developed secondary VZV infection. The incidence of secondary VZV infection was significantly lower in the PEP group than in the non-PEP group (P=0.036). Among patients administered PEP, no antiviral drug-induced side effects were detected. Conclusions Antiviral agents administered as PEP are effective and safe for preventing VZV infections in immunocompromised patients. Rapid virological diagnosis of index cases might allow efficient administration of PEP after significant exposure to VZV infection.
Collapse
|
7
|
Abstract
Here, we present a previously healthy adolescent with aseptic meningitis without skin rash caused by varicella vaccine derived from the Oka/Biken strain; the patient received a single dose of varicella vaccine at 1 year of age. Pediatricians should be aware of the potential for reactivation of varicella vaccine derived from the Oka/Biken strain, which can cause aseptic meningitis in vaccinated children even in the absence of a skin rash.
Collapse
|
8
|
Epidemiological impact of universal varicella vaccination on consecutive emergency department visits for varicella and its economic impact among children in Kobe City, Japan. J Infect Chemother 2021; 28:35-40. [PMID: 34620534 DOI: 10.1016/j.jiac.2021.09.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 09/17/2021] [Accepted: 09/24/2021] [Indexed: 11/22/2022]
Abstract
INTRODUCTION Previous studies reported a dramatic decline in the incidence of varicella and varicella-related deaths after implementing universal varicella vaccination (VarV). Although previous studies reported the effectiveness and economic impact of VarV, they were unknown in the emergency department (ED) setting. METHODS To determine the effectiveness and economic impact of VarV in the ED, Kobe, Japan, we retrospectively reviewed the clinical database of consecutive patients younger than 16 years presenting to our primary ED from 2011 to 2019. RESULTS Of the 265,191 children presenting to our ED, 3,092 patients were clinically diagnosed with varicella. The number of patients with varicella was approximately 500 annually, before introducing the universal two-dose VarV for children aged 1 to <3 years in October 2014, in the Japanese national immunization program, and decreased to approximately 200 in 2019. The number of patients with varicella younger than 1 year (ineligible for the vaccination) also decreased. Regarding the economic impact, the medical cost in our ED reduced after the introduction of VarV was JPY 4.1 million (US$ 40,049) annually. From the central data, approximately 95% of children were vaccinated after October 2014; however, a relatively large percentage of infected unvaccinated children (59.0%) presented to ED in this study. After the implementation of the universal VarV, infection was mainly observed in older children (i.e., the unvaccinated generation). CONCLUSIONS Our data showed the effectiveness and economic impact of VarV in the ED setting. Additionally, our data suggested that the public vaccination program should include older unvaccinated children and other unvaccinated individuals.
Collapse
|
9
|
Yoshikawa T. Implementing vaccination policies based upon scientific evidence in Japan. Vaccine 2021; 39:5447-5450. [PMID: 34373119 PMCID: PMC8346366 DOI: 10.1016/j.vaccine.2021.07.075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 07/17/2021] [Accepted: 07/26/2021] [Indexed: 01/29/2023]
Abstract
The theme of the 24th Annual Meeting of the Japanese Society for Vaccinology was “Sustainable Future Medical Care Created by Vaccines.” This theme includes topics such as the proposal to reduce the medical costs incurred by societies with aging populations through prophylactic vaccination. The coronavirus disease 2019 (COVID-19) pandemic alerted us to the important roles that preventive measures, such as vaccines, play in fighting infectious diseases. In order to inform the public of the benefits of vaccines, it is important to provide society with information regarding new vaccine developments, adjuvants, the cost–benefit ratio of vaccine introduction, and vaccine effectiveness and safety. Clinical research is essential for obtaining evidence of vaccine effectiveness and safety. The United States Centers for Disease Control and Prevention (CDC) conducts active surveillance in defined areas before and after the introduction of vaccines and documents the reduction in infection rates as a measure of vaccine effectiveness. However, vaccine efficacy and side effects may vary by country and ethnicity. Therefore, it is necessary for individual countries to develop their own evidence-based surveillance programs. We have studied vaccine efficacy and documented side-effects observed in patients for the varicella and rotavirus vaccines in Japan. This review outlines the importance of providing scientific evidence for vaccine effectiveness and safety.
Collapse
Affiliation(s)
- Tetsushi Yoshikawa
- Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Aichi, Japan.
| |
Collapse
|
10
|
Yasui Y, Mitsui T, Arima F, Uchida K, Inokuchi M, Tokumura M, Nakayama T. Changes in epidemiological characteristics and sero-prevalence against the varicella zoster virus in school-age children after the introduction of a national immunization program in Japan. Hum Vaccin Immunother 2021; 17:2494-2500. [PMID: 33650932 DOI: 10.1080/21645515.2021.1890968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
A national immunization program using two doses of live attenuated varicella vaccine was introduced for children aged one to two years in Japan in October 2014. Varicella cases declined after 2014, and immunological status against varicella among vaccinated children changed in post-vaccination era. A retrospective observational study of anti-varicella antibody seroprevalence, varicella vaccination status, and history of varicella among 528 students in the first grade of elementary school was conducted. The percentage of students who received at least a single dose of varicella vaccination increased from 67% (187 of 279 students) in 2007-2008 to 91% (226 of 249 students) in 2017. Students with a history of varicella decreased from 114 of 279 (41%) in 2007-2008 to 48 of 249 (19%, P < .01) in 2017. Among them, the rate of breakthrough varicella after a single dose of vaccine in students with a history of varicella significantly increased from 38% (43 of 114 students) in 2007-2008 to 58% (28 of 48 students) in 2017 (P < .05). The antibody-positive rate significantly decreased from 50% among subjects without varicella zoster who received a single dose (95%CI: 41-58%) in 2007-2008 to 29% (95%CI: 21-38%) in 2017 (P < .01). The antibody-positive rate among students without varicella history who received two doses of vaccine was only 43% (95%CI: 32-55%) in 2017. The number of varicella infections and antibody-positive rate among students without history of varicella who received varicella vaccination decreased after the introduction of a national immunization program.
Collapse
Affiliation(s)
- Yosuke Yasui
- Health Center, Keio University, Kanagawa, Japan.,Kitasato Institute for Life Sciences, Tokyo, Japan
| | | | | | | | | | | | | |
Collapse
|
11
|
Kawamura Y, Hattori F, Higashimoto Y, Kozawa K, Yoshikawa T. Evaluation of varicella vaccine effectiveness during outbreaks in schools or nurseries by cross-sectional study. Vaccine 2021; 39:2901-2905. [PMID: 33895017 DOI: 10.1016/j.vaccine.2021.04.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/26/2021] [Accepted: 04/02/2021] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The aim of this study was to elucidate vaccine effectiveness (VE) during varicella outbreaks in schools and nurseries in Japan. METHODS An outbreak was defined as emergence of three or more cases of varicella within 21 days at the same institute. Clinical information such as varicella vaccination status, and history of varicella was collected. If a child had varicella during the outbreak, information about absences, fever, and disease severity was collected. RESULTS From September 2018 to January 2020, four outbreaks were reported around our institute from three elementary schools and one nursery. A total of 676 children were analyzed in this study. Seventy-six children (11.2%) were unvaccinated, 309 (45.7%) had received one dose of vaccine, and 291 (43.0%) had received two doses. Most children in Pre-K2 (1-2 years old) to Pre-K6 (5-6 years old), who were the targets of the national immunization schedule, received two doses. Meanwhile, most children older than third grade received single dose. Seventy-five children (11.1%) had varicella. Varicella prevalence from Pre-K5 to the third grade was greater than 10%. The adjusted VEs of single- and two-dose of varicella vaccine were 57.8% and 89.0%. The number of days absent was significantly longer in unvaccinated children than single-dose recipients (P = 0.0145). Unvaccinated children had significantly more severe skin eruptions than single-dose recipients (P = 0.0046) and two-dose recipients (P = 0.0258). CONCLUSIONS Although VEs of single-dose varicella vaccination during outbreaks was not high, the VE of two-dose vaccination was similar to that in a previously reported case-control study.
Collapse
Affiliation(s)
- Yoshiki Kawamura
- Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan.
| | - Fumihiko Hattori
- Department of Pediatrics, Kariya Toyota General Hospital, Kariya, Aichi, Japan
| | - Yuki Higashimoto
- Faculty of Medical Technology, Fujita Health University School of Medical Sciences, Toyoake, Aichi, Japan
| | - Kei Kozawa
- Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan
| | - Tetsushi Yoshikawa
- Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan
| |
Collapse
|
12
|
Suh J, Lee T, Choi JK, Lee J, Park SH. The impact of two-dose varicella vaccination on varicella and herpes zoster incidence in South Korea using a mathematical model with changing population demographics. Vaccine 2021; 39:2575-2583. [PMID: 33814230 DOI: 10.1016/j.vaccine.2021.03.056] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 03/13/2021] [Accepted: 03/16/2021] [Indexed: 01/29/2023]
Abstract
BACKGROUND In South Korea, one-dose varicella vaccination was introduced to the National Immunization Program in 2005, but varicella outbreaks have continued to occur. Therefore, a two-dose vaccination strategy is considered. METHODS We developed an age-structured deterministic compartment model using Korean population projection data. The impact of adding a second dose of varicella vaccine on varicella and herpes zoster (HZ) epidemiology was assessed under four different vaccine effectiveness (VE) scenarios (base, moderate, lowest, highest) and the optimal timing of the second vaccine dose (18 months, 4, 5, or 6 years of age) was examined over the period 2020-2065. RESULTS A two-dose vaccination schedule reduced the cumulative varicella incidence by > 90% compared to no vaccination, regardless of the VE. The additional reduction attributable to a second dose compared to a single dose was greatest (82%) with the lowest VE scenario. A second dose at 6 years of age reduced the varicella incidence at a population level, whereas a second dose at 18 months of age reduced the varicella incidence primarily in the target birth cohorts. Routine vaccination at the age of 18 months with a catch-up vaccination of 6-year-olds was the optimal strategy for birth cohort and population-level control. HZ incidence continued to increase under no vaccination scenario, which represents the effect of aging population. Under a two-dose scenario, the additional increase in HZ incidence attributable to the reduced exogenous boosting was small relative to a one-dose scenario and a further reduction in HZ cases was observed. CONCLUSION A two-dose varicella vaccination schedule would significantly reduce varicella and HZ incidence in the long term. A second dose at the age of 18 months with a catch-up vaccination of 6-year-olds would be optimal for controlling varicella in South Korea.
Collapse
Affiliation(s)
- Jiyeon Suh
- School of Mathematics and Computing (Computational Science and Engineering), Yonsei University, Seoul, Republic of Korea
| | - Taeyong Lee
- School of Mathematics and Computing (Mathematics), Yonsei University, Seoul, Republic of Korea
| | - Jae-Ki Choi
- Division of Infectious Diseases, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Jeehyun Lee
- School of Mathematics and Computing (Computational Science and Engineering), Yonsei University, Seoul, Republic of Korea; School of Mathematics and Computing (Mathematics), Yonsei University, Seoul, Republic of Korea.
| | - Sun Hee Park
- Division of Infectious Diseases, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
| |
Collapse
|
13
|
Hattori F, Kozawa K, Miura H, Kawamura Y, Higashimoto Y, Yoshikawa A, Ihira M, Yoshikawa T. Trend in varicella patients 4 years after implementation of universal two-dose varicella vaccination in Japan. Vaccine 2020; 38:7331-7336. [PMID: 33008671 DOI: 10.1016/j.vaccine.2020.09.038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 09/05/2020] [Accepted: 09/13/2020] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To elucidate the trend and clinical spectrum of virologically diagnosed varicella patients after implementation of universal vaccination as a national immunization program in Japan. PATIENTS AND METHODS Study subjects were patients suspected of varicella, less than 15 years of age, who visited 14 pediatric clinics in the Nagoya VZV Study Group from September 2015 to August 2019. Practitioners collected patient samples and information such as backgrounds, clinical symptoms, and previous immunization status. All patients were confirmed as having varicella based on molecular diagnostic assays. RESULTS Varicella zoster virus (VZV) DNA was detected in swab samples from 506 (83.1%) of the 609 suspected patients. The 455 varicella patients for whom vaccination status was available were divided into two groups: 180 universal vaccination targets and 275 non-targets. Numbers of monthly varicella patients decreased gradually during the observation period. In the 2016/17 season, the seasonal epidemic of varicella became undetectable in the universal vaccination target group, and starting in the 2017/18 season, it was obscured even in the non-target group. The median age of patients was significantly lower in the universal vaccination target group (3 years) than the non-target group (7 years) (P < 0.001). Vaccination status differed significantly between the two groups (P < 0.001). Most varicella patients were in the non-target group, especially those who had been vaccinated once (60.4%). Frequency of fever (P < 0.001) and number of skin rashes at the time of the first hospital visit (P = 0.001) were significantly higher in the non-target group. CONCLUSIONS Although the number of childhood varicella patients declined after implementation of national immunization with two doses of varicella vaccination, sporadic outbreaks still occurred, mainly in the non-universal vaccination target group. Insufficient vaccination of members of this group is likely to be a major reason for small local outbreaks.
Collapse
Affiliation(s)
- Fumihiko Hattori
- Department of Pediatrics, Kariya Toyota General Hospital, Kariya, Aichi 448-8505, Japan; Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Aichi, Japan.
| | - Kei Kozawa
- Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
| | - Hiroki Miura
- Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
| | - Yoshiki Kawamura
- Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
| | - Yuki Higashimoto
- Faculty of Medical Technology, Fujita Health University School of Medical Sciences, Toyoake, Aichi, Japan
| | - Akiko Yoshikawa
- Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
| | - Masaru Ihira
- Faculty of Clinical Engineering, Fujita Health University School of Medical Sciences, Toyoake, Aichi, Japan
| | - Tetsushi Yoshikawa
- Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
| | | |
Collapse
|
14
|
Barrenechea GG, Bastos LS. Evaluation of impact of one dose varicella vaccine on the incidence of chickenpox in Argentina. Vaccine 2019; 38:330-335. [PMID: 31630938 DOI: 10.1016/j.vaccine.2019.10.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 09/30/2019] [Accepted: 10/02/2019] [Indexed: 12/01/2022]
Abstract
INTRODUCTION Varicella, also known as chickenpox is one of the most common immunizable diseases. In 1998, the World Health Organization (WHO) recommended to incorporate this vaccine in the national immunization programs, which Argentina did in 2015. OBJECTIVES To describe the behavior of the varicella time series for the 2005-2017 period, and to evaluate the impact of the vaccine in Argentina. METHODOLOGY An ecological observational study was performed, using the varicella cases reported in the National Health Monitoring System, and the data of the National census as secondary data sources. A model based time series analysis of the notified varicella cases in Argentina was performed, using a Negative Binomial Mixed Model. For the verification of the vaccine impact, the 2005-2014 period was selected, and a prognosis for the following years was performed. Impact was evaluated by comparing the rates and confidence intervals between the predicted and observed values. RESULTS Argentina reported 1,775,587 varicella cases for the 2005-2017 period. The series exhibited seasonality, and, a decreasing trend in the number of cases was observed in 2016 and 2017. A reduction of the incidence rate after the implementation of the vaccine was observed. The transmission risk decreased in the country after vaccine implementation. CONCLUSIONS This study is the first concrete evidence of the varicella incidence decline after the implementation of a single dose application program in Argentina.
Collapse
Affiliation(s)
- Guillermo G Barrenechea
- Departamento Bioquímico-Laboratorio de Salud Pública, Mendoza 128 4° Piso, San Miguel de Tucumán, Tucumán CP: 4107, Argentina; Dirección de Investigación en Salud, Virgen de la Merced 189 1° Piso, San Miguel de Tucumán, Tucumán CP: 4107, Argentina.
| | - Leonardo S Bastos
- Scientific Computing Program, Oswaldo Cruz Foundation, Av. Brasil, 4365, Manguinhos, Rio de Janeiro CEP: 21040-900, Brazil; Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| |
Collapse
|
15
|
Varela FH, Pinto LA, Scotta MC. Global impact of varicella vaccination programs. Hum Vaccin Immunother 2018; 15:645-657. [PMID: 30427766 PMCID: PMC6605725 DOI: 10.1080/21645515.2018.1546525] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Revised: 10/12/2018] [Accepted: 10/29/2018] [Indexed: 12/19/2022] Open
Abstract
Although varicella is usually a mild and self-limited disease, complications can occur. In 1998, the World Health Organization recommended varicella vaccination for countries where the disease has a significant public health burden. Nonetheless, concerns about a shift in the disease to older groups, an increase in herpes zoster in the elderly and cost-effectiveness led many countries to postpone universal varicella vaccine introduction. In this review, we summarize the accumulating evidence, available mostly from high and middle-income countries supporting a high impact of universal vaccination in reductions of the incidence of the disease and hospitalizations and its cost-effectiveness. We have also observed the effect of herd immunity and noted that there is no definitive and consistent association between vaccination and the increase in herpes zoster incidence in the elderly.
Collapse
Affiliation(s)
- Fernanda Hammes Varela
- Centro Infant, Department of Pediatrics, School of Medicine, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Rio Grande do Sul state, Brazil
| | - Leonardo Araújo Pinto
- Centro Infant, Department of Pediatrics, School of Medicine, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Rio Grande do Sul state, Brazil
| | - Marcelo Comerlato Scotta
- Centro Infant, Department of Pediatrics, School of Medicine, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Rio Grande do Sul state, Brazil
| |
Collapse
|
16
|
Morino S, Tanaka-Taya K, Satoh H, Arai S, Takahashi T, Sunagawa T, Oishi K. Descriptive epidemiology of varicella based on national surveillance data before and after the introduction of routine varicella vaccination with two doses in Japan, 2000-2017. Vaccine 2018; 36:5977-5982. [PMID: 30166199 DOI: 10.1016/j.vaccine.2018.08.048] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Revised: 08/17/2018] [Accepted: 08/21/2018] [Indexed: 11/15/2022]
Abstract
Routine childhood immunization using two doses of the varicella vaccine was introduced in Japan in October 2014. In this study, we analyzed the data extracted from national varicella surveillance, including pediatric sentinel surveillance from 2000 to 2017 and hospitalized varicella surveillance from the 38th week of 2014 to the 37th week of 2017. Compared with the 2000-2011 baseline data, the number of varicella cases per sentinel decreased substantially by 76.6% overall and by 88.2% among children aged 1-4 years in 2017. Of 997 hospitalized patients, we found a decreasing trend in the number of cases among children aged <5 years. We also found a decreasing trend in the number of cases with complications among children aged 1-4 years. Data on the self-reported transmission sites in 35.5% (354/997) of the hospitalized varicella patients showed that transmission of varicella zoster virus (VZV) occurred frequently in household, at school for young children, in the workplace for adults, and at hospital for all age groups. Data from 29.0% (289/997) of the hospitalized patients with a self-reported source of infection showed that transmission of VZV occurred from a patient with herpes zoster (HZ) in 30.4% (88/289) of cases. Our data demonstrate a substantial decrease in the number of varicella cases in young children following introduction of routine childhood vaccination program with two-dose varicella vaccination in Japan. These data highlight the unique aspects of transmission sites across age groups and the important role of HZ cases in disease circulation.
Collapse
Affiliation(s)
- Saeko Morino
- Infectious Disease Surveillance Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Keiko Tanaka-Taya
- Infectious Disease Surveillance Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Hiroshi Satoh
- Infectious Disease Surveillance Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Satoru Arai
- Infectious Disease Surveillance Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Takuri Takahashi
- Infectious Disease Surveillance Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Tomimasa Sunagawa
- Infectious Disease Surveillance Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Kazunori Oishi
- Infectious Disease Surveillance Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan.
| |
Collapse
|