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Hempel K, McDonald W, Osgood ND, Fisman D, Halperin SA, Crowcroft N, Klein NP, Rohani P, Doroshenko A. Evaluation of the effectiveness of maternal immunization against pertussis in Alberta using agent-based modeling: A Canadian immunization research network study. Vaccine 2023; 41:2430-2438. [PMID: 36775775 DOI: 10.1016/j.vaccine.2022.12.071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 12/05/2022] [Accepted: 12/13/2022] [Indexed: 02/12/2023]
Abstract
INTRODUCTION The re-emergence of pertussis has occurred in the past two decades in developed countries. The highest morbidity and mortality is seen among infants. Vaccination in pregnancy is recommended to reduce the pertussis burden in infants. METHODS We developed and validated an agent-based model to characterize pertussis epidemiology in Alberta. We computed programmatic effectiveness of pertussis vaccination during pregnancy (PVE) in relation to maternal vaccine coverage and pertussis disease reporting thresholds. We estimated the population preventable fraction (PFP) of different levels of maternal vaccine coverage against counterfactual "no-vaccination" scenario. We modeled the effect of immunological blunting and measured protection through interruption of exposure pathways. RESULTS PVE was inversely related to duration of passive immunity from maternal immunization across most simulations. In the scenario of 50% maternal vaccine coverage, PVE was 87% (95% quantiles 82-91%), with PFP of 44% (95% quantiles 41-45%). For monthly age intervals of 0-2, 2-4, 4-6 and 6-12, PVE ranged between 82 and 99%, and PFP ranged between 41 and 49%. At 75% maternal vaccine coverage, PVE and PFP were 90% (95% quantiles 86-92%) and 68% (95% quantiles 65-69%), respectively. At 50% maternal vaccine coverage and 10% blunting, PVE and PFP were 86% (95% quantiles 77-87%) and 43% (95% quantiles 39-44%), respectively, while at 50% blunting, the corresponding values of PVE and PFP were 76% (95% quantiles 70-81%) and 38% (95% quantiles 35-40%). PVE attributable to interruption of exposure pathways was 54-57%. CONCLUSIONS Our model predicts significant reduction in future pertussis cases in infants due to maternal vaccination, with immunological blunting slightly moderating its effectiveness. The model is most sensitive to maternal vaccination coverage. The interruption of exposure pathways plays a role in the reduction of pertussis burden in infants due to maternal immunization. The effect of maternal immunization on population other than infants remains to be elucidated.
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Affiliation(s)
- Karsten Hempel
- Department of Medicine, Division of Preventive Medicine, College of Health Sciences, University of Alberta, Edmonton, Alberta, Canada.
| | - Wade McDonald
- Department of Computer Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
| | - Nathaniel D Osgood
- Department of Computer Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - David Fisman
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
| | - Scott A Halperin
- Departments of Pediatrics, Microbiology and Immunology, Canadian Center for Vaccinology, Dalhousie University, Halifax, Nova Scotia, Canada.
| | - Natasha Crowcroft
- World Health Organization, Geneva, Switzerland; Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
| | - Nicola P Klein
- Kaiser Permanente Vaccine Study Center, Kaiser Permanente Northern California, Oakland, CA, USA.
| | - Pejman Rohani
- Department of Infectious Diseases, University of Georgia, Athens, GA, USA; Odum School of Ecology, University of Georgia, Athens, GA, USA.
| | - Alexander Doroshenko
- Department of Medicine, Division of Preventive Medicine, College of Health Sciences, University of Alberta, Edmonton, Alberta, Canada; School of Public Health, College of Health Sciences, University of Alberta, Edmonton, Alberta, Canada.
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Ozaki T, Nishimura N, Gotoh K, Takemoto K. Anti-varicella-zoster virus antibody titers and seroprotection status from before the first dose of varicella vaccination to before entering elementary school in one region in Japan. Vaccine 2023; 41:1274-1279. [PMID: 36631357 DOI: 10.1016/j.vaccine.2023.01.010] [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: 08/23/2022] [Revised: 12/08/2022] [Accepted: 12/14/2022] [Indexed: 01/11/2023]
Abstract
OBJECTIVE We aimed to examine changes in anti-varicella-zoster virus (VZV) antibody titers and seroprotection status from before the first dose of vaccination to before 7 years old entering elementary school in children who received the routine two-dose varicella vaccination. METHODS Participants were 37 healthy children who received the routine two-dose varicella vaccination at our hospital. A total of five serum samples per child were collected immediately before and 4-6 weeks after each dose of the vaccination and in the year before entry to elementary school. We measured anti-VZV antibody titers by immune adherence hemagglutination (IAHA) method and glycoprotein-based enzyme-linked immunosorbent assay (gpELISA). A positive antibody titer and the seroprotection level were set as ≥2-fold and ≥16-fold, respectively, for IAHA antibody and as ≥50 units and ≥105 units, respectively, for gpELISA-IgG antibody. RESULTS The rates of IAHA antibody positivity in the five samples (in order of collection) were 0%, 65%, 38%, 100%, and 59%, and the rates of seroprotection were 0%, 43%, 8%, 100%, and 43%. The rates of gpELISA-IgG antibody positivity were 8%, 81%, 89%, 100%, and 100%, and the rates of seroprotection were 5%, 54%, 70%, 100%, and 89%. The mean IAHA antibody titer and mean gpELISA-IgG antibody titer before entering elementary school were both lower than the respective titers obtained after the second vaccination (both p < 0.01). CONCLUSIONS Routine two-dose varicella vaccination leads to good antibody production, but titers of acquired antibodies decrease before children enter elementary school.
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Affiliation(s)
- Takao Ozaki
- Department of Pediatrics, Konan Kosei Hospital, Konan, Aichi 483-8704, Japan.
| | - Naoko Nishimura
- Department of Pediatrics, Konan Kosei Hospital, Konan, Aichi 483-8704, Japan
| | - Kensei Gotoh
- Department of Pediatrics, Konan Kosei Hospital, Konan, Aichi 483-8704, Japan
| | - Koji Takemoto
- Department of Pediatrics, Konan Kosei Hospital, Konan, Aichi 483-8704, Japan
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Sun X, Dai C, Wang K, Liu Y, Jin X, Wang C, Yin Y, Ding Z, Lu Z, Wang W, Wang Z, Tang F, Wang K, Peng Z. A Dynamic Compartmental Model to Explore the Optimal Strategy of Varicella Vaccination: An Epidemiological Study in Jiangsu Province, China. Trop Med Infect Dis 2022; 8:tropicalmed8010017. [PMID: 36668924 PMCID: PMC9861499 DOI: 10.3390/tropicalmed8010017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 12/11/2022] [Accepted: 12/23/2022] [Indexed: 12/28/2022] Open
Abstract
Varicella (chickenpox) is highly contagious among children and frequently breaks out in schools. In this study, we developed a dynamic compartment model to explore the optimal schedule for varicella vaccination in Jiangsu Province, China. A susceptible-infected-recovered (SIR) model was proposed to simulate the transmission of varicella in different age groups. The basic reproduction number was computed by the kinetic model, and the impact of three prevention factors was assessed through the global sensitivity analysis. Finally, the effect of various vaccination scenarios was qualitatively evaluated by numerical simulation. The estimated basic reproduction number was 1.831 ± 0.078, and the greatest contributor was the 5-10 year-old group (0.747 ± 0.042, 40.80%). Sensitivity analysis indicated that there was a strong negative correlation between the second dose vaccination coverage rate and basic reproduction number. In addition, we qualitatively found that the incidence would significantly decrease as the second dose vaccine coverage expands. The results suggest that two-dose varicella vaccination should be mandatory, and the optimal age of second dose vaccination is the 5-10 year-old group. Optimal vaccination time, wide vaccine coverage along with other measures, could enhance the effectiveness of prevention and control of varicella in China.
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Affiliation(s)
- Xiang Sun
- Department of Expanded Program on Immunization, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing 210009, China
| | - Chenxi Dai
- Department of Biomedical Engineering and Imaging Medicine, Army Medical University, Chongqing 400038, China
| | - Kai Wang
- The First Clinical Medical College of Nanjing Medical University, Nanjing 210029, China
| | - Yuanbao Liu
- Department of Expanded Program on Immunization, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing 210009, China
| | - Xinye Jin
- Department of Epidemiology and Biostatistics, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Congyue Wang
- Department of Epidemiology and Biostatistics, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Yi Yin
- Department of Epidemiology and Biostatistics, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Zhongxing Ding
- Department of Epidemiology and Biostatistics, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Zhenzhen Lu
- Department of Epidemiology and Biostatistics, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Weiming Wang
- Department of Mathematics and Statistics, Huaiyin Normal University, Huaian 223300, China
| | - Zhiguo Wang
- Department of Expanded Program on Immunization, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing 210009, China
| | - Fenyang Tang
- Department of Expanded Program on Immunization, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing 210009, China
- Correspondence: (F.T.); (K.W.); (Z.P.); Tel.: +86-25-83759423 (F.T.); +86-23-68771726 (K.W.); +86-25-86868244 (Z.P.)
| | - Kaifa Wang
- Department of Mathematics and Statistics, Southwest University, Chongqing 400715, China
- Correspondence: (F.T.); (K.W.); (Z.P.); Tel.: +86-25-83759423 (F.T.); +86-23-68771726 (K.W.); +86-25-86868244 (Z.P.)
| | - Zhihang Peng
- Department of Epidemiology and Biostatistics, School of Public Health, Nanjing Medical University, Nanjing 211166, China
- Correspondence: (F.T.); (K.W.); (Z.P.); Tel.: +86-25-83759423 (F.T.); +86-23-68771726 (K.W.); +86-25-86868244 (Z.P.)
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Wang Q, Xiu S, Yang L, Huang J, Cui T, Shi N, Wang X, Shen Y, Chen E, Lu B, Jin H, Lin L. Economic evaluation of varicella vaccination strategies in Jiangsu province, China: a decision-tree Markov model. Hum Vaccin Immunother 2021; 17:4194-4202. [PMID: 34357833 DOI: 10.1080/21645515.2021.1958608] [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: 10/20/2022] Open
Abstract
This study evaluated different varicella vaccination strategies in Jiangsu province, China. A decision-tree Markov model was used to evaluate the cost effectiveness of various varicella vaccination strategies for children, including direct and selective vaccination (serotesting pre-vaccination). A cohort of one-year-old children was followed through 60 one-year Markov cycles. The parameter estimation was based on field work, the literature, and statistical yearbooks. We calculated the incremental cost-utility ratio (ICUR) using the saved quality-adjusted life year (QALY). One-way and probability sensitivity analyses were performed to assess uncertainty. Among 100,000 cohort members, one-dose and two-dose direct vaccination averted 8061 and 10,701 varicella cases, respectively, compared with no vaccination. Furthermore, compared with no vaccination, one-dose and two-dose direct vaccination saved one QALY at the ICUR of USD 21,401.33 and USD 35,420.81, respectively, at less than three times the per capita gross domestic product (USD 47,626.86) of Jiangsu. The ICURs of the one-dose and two-dose selective strategies versus no vaccination were USD 42,623.62 and USD 51,406.35 per QALY gained, respectively. The cost effectiveness results were most sensitive to the QALY loss of outpatients and vaccine prices. Thus, in Jiangsu, one-dose and two-dose direct varicella vaccination in children could be cost effective at the willingness to pay threshold of three times provincial GDP per capita from a societal perspective. The findings were sensitive to the vaccine price and health utility of varicella cases.
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Affiliation(s)
- Qiang Wang
- Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, PR China.,Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, PR China
| | - Shixin Xiu
- Department of Immunization Planning, Wuxi Center for Disease Control and Prevention, Wuxi, PR China
| | - Liuqing Yang
- Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, PR China.,Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, PR China
| | - Jinxin Huang
- Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, PR China.,Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, PR China
| | - Tingting Cui
- Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, PR China.,Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, PR China
| | - Naiyang Shi
- Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, PR China.,Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, PR China
| | - Xuwen Wang
- Department of Immunization Planning, Wuxi Center for Disease Control and Prevention, Wuxi, PR China
| | - Yuan Shen
- Department of Immunization Planning, Wuxi Center for Disease Control and Prevention, Wuxi, PR China
| | - Enpin Chen
- Department of Immunization Planning, Wuxi Center for Disease Control and Prevention, Wuxi, PR China
| | - Bing Lu
- Department of Immunization Planning, Wuxi Center for Disease Control and Prevention, Wuxi, PR China
| | - Hui Jin
- Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, PR China.,Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, PR China
| | - Leesa Lin
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK.,Laboratory of Data Discovery for Health (D24H), Hong Kong Science Park, Hong Kong, China
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Heininger U, Pillsbury M, Samant S, Lienert F, Guggisberg P, Gani R, O'Brien E, Pawaskar M. Health Impact and Cost-effectiveness Assessment for the Introduction of Universal Varicella Vaccination in Switzerland. Pediatr Infect Dis J 2021; 40:e217-e221. [PMID: 33872276 DOI: 10.1097/inf.0000000000003136] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Varicella, caused by the varicella-zoster virus, is a highly contagious infectious disease with substantial health and economic burden to society. Universal varicella vaccination (UVV) is not yet recommended by the Swiss National Immunization Program, which instead recommends catch-up immunization for children, adolescents and adults 11-40 years of age who have no reliable history of varicella or are varicella-zoster virus-IgG seronegative. The objective of this study was to perform an assessment of health impact and cost-effectiveness comparing UVV with current practice and recommendations in Switzerland. METHODS A dynamic transmission model for varicella was adapted to Switzerland comparing 2 base-case schedules (no infant vaccination and 10% coverage with infant vaccination) to 3 different UVV schedules using quadrivalent (varicella vaccine combined with measles-mumps-rubella) and standalone varicella vaccines administered at different ages. Modeled UVV coverage rates were based on current measles-mumps-rubella coverage of approximately 95% (first dose) and 90% (second dose). Direct medical costs and societal perspectives were considered, with cost and outcomes discounted and calculated over a 50-year time horizon. RESULTS UVV would reduce the number of varicella cases by 88%-90%, hospitalizations by 62%-69% and deaths by 75%-77%. UVV would increase direct medical costs by Swiss Franc (CHF) 39-49 (US $43-54) per capita and costs from a societal perspective by CHF 32-40 (US $35-44). Incremental quality-adjusted life-years per capita increased by 0.0012-0.0014. Incremental cost-effectiveness ratios for the UVV schedules versus the base-case were CHF 31,194-35,403 (US $34,452-39,100) per quality-adjusted life-year from the direct medical cost perspective and CHF 25,245-29,552 (US $27,881-32,638) from the societal perspective. CONCLUSIONS UVV appears highly effective and cost-effective when compared with current clinical practice and recommendations in Switzerland from both a direct medical costs perspective and societal perspective.
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Affiliation(s)
- Ulrich Heininger
- From the University of Basel Children's Hospital, Basel, Switzerland
| | - Matthew Pillsbury
- Center for Observational and Real-World Evidence, Merck & Co., Inc., Kenilworth, New Jersey
| | - Salome Samant
- Center for Observational and Real-World Evidence, Merck & Co., Inc., Kenilworth, New Jersey
| | | | | | | | | | - Manjiri Pawaskar
- Center for Observational and Real-World Evidence, Merck & Co., Inc., Kenilworth, New Jersey
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Rafferty ERS, McDonald W, Osgood ND, Doroshenko A, Farag M. What We Know Now: An Economic Evaluation of Chickenpox Vaccination and Dose Timing Using an Agent-Based Model. VALUE IN HEALTH : THE JOURNAL OF THE INTERNATIONAL SOCIETY FOR PHARMACOECONOMICS AND OUTCOMES RESEARCH 2021; 24:50-60. [PMID: 33431153 DOI: 10.1016/j.jval.2020.10.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 09/03/2020] [Accepted: 10/05/2020] [Indexed: 06/12/2023]
Abstract
OBJECTIVES The value of chickenpox vaccination is still debated in the literature and by jurisdictions worldwide. This uncertainty is reflected in the inconsistent uptake of the vaccine, where some countries offer routine childhood immunization programs, others have targeted programs, and in many the vaccine is only privately available. Even across the countries that have universal funding for the vaccine, there is a diversity of schedules and dosing intervals. Using an agent-based model of chickenpox and shingles, we conducted an economic evaluation of chickenpox vaccination in Alberta, Canada. METHODS We compared the cost-effectiveness of 2 common chickenpox vaccination schedules, specifically a long dosing interval (first dose: 12 months; second dose: 4-6 years) and a short dosing interval (first dose: 12 months; second dose: 18 months). RESULTS The economic evaluation demonstrated a shorter dosing interval may be marginally preferred, although it consistently led to higher costs from both the societal and healthcare perspectives. We found that chickenpox vaccination would be cost-saving and highly cost-effective from the societal and healthcare perspective, assuming there was no impact on shingles. CONCLUSION Chickenpox vaccine was cost-effective when not considering shingles and remained so even if there was a minor increase in shingles following vaccination. However, if chickenpox vaccination did lead to a substantial increase in shingles, then chickenpox vaccination was not cost-effective from the healthcare perspective.
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Affiliation(s)
- Ellen R S Rafferty
- School of Public Health, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; Faculty of Nursing, Edmonton Clinic Health Academy, University of Alberta, Edmonton, Alberta, Canada.
| | - Wade McDonald
- Department of Computer Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Nathaniel D Osgood
- Department of Computer Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Alexander Doroshenko
- Faculty of Medicine and Dentistry, Department of Medicine, Division of Preventive Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Marwa Farag
- School of Public Health, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; School of Public Administration and Development Economics, Doha Institute for Graduate Studies, Doha, Qatar
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