Cost-effectiveness analysis of universal adult immunization with tetanus-diphtheria-acellular pertussis vaccine (Tdap) versus current practice in Brazil Eder Gatti Fernandes a,b,⇑ , Ana Marli Christovam Sartori c,d , Patrícia Coelho de Soárez e,d , Marcos Amaku f , Raymundo Soares de Azevedo Neto f , Hillegonda Maria Dutilh Novaes e,d a Departamento de Medicina Preventiva, Faculdade de Medicina da Universidade de São Paulo, Av. Dr. Arnaldo, 455 2° andar, sala 2228, CEP: 01246-903 São Paulo, SP, Brazil b Divisão de Imunização, Centro de Vigilância Epidemiológica ‘‘Prof. Alexandre Vranjac”, Coordenadoria de Controle de Doenças da Secretaria de Estado da Saúde de São Paulo, Av. Dr Arnaldo, 351, 6° andar, Pacaembu, CEP: 01246-000 São Paulo, SP, Brazil c Departamento de Moléstias Infecciosas e Parasitárias, Faculdade de Medicina da Universidade de São Paulo, Av. Dr. Enéas de Carvalho Aguiar, 255, ICHC, 4° andar, sala 4028 Cerqueira César, CEP: 05403-000 São Paulo, SP, Brazil d Health Technology Assessment Institute (IATS), Brazil e Departamento de Medicina Preventiva, Faculdade de Medicina da Universidade de São Paulo, Av. Dr. Arnaldo, 455, CEP: 01246-903 São Paulo, SP, Brazil f Departamento de Patologia, Faculdade de Medicina da Universidade de São Paulo, Av. Dr. Arnaldo, 455, CEP: 01246-903 São Paulo, SP, Brazil article info Article history: Received 6 March 2019 Received in revised form 30 September 2019 Accepted 30 September 2019 Available online xxxx Keywords: Cost-benefit analysis Cost-effectiveness analysis Diphtheria-tetanus-acellular pertussis vaccines Pertussis vaccine Whooping cough Adult abstract Background: A pertussis outbreak occurred in Brazil from 2011 to 2014, despite high coverage of whole- cell pertussis containing vaccines in early childhood. Infants were the most affected. This study aimed to evaluate the cost-effectiveness of introducing universal adult vaccination with Tdap into the National Immunization Program in Brazil. Methods: Economic evaluation using a dynamic model to compare two strategies: (1) universal vaccina- tion with single dose of Tdap at 20 years of age and (2) current practice (only pregnant women pertussis vaccination). The health system perspective was adopted. Temporal horizon was 10 years. Discount rate of 5% was applied to costs and benefits. Vaccine effectiveness (VE) was obtained from a population-based observational study. Epidemiological, resource utilization and cost estimates were obtained from the Brazilian Health Information Systems. The primary outcome was cost per life year saved (LYS), based on life expectancy at birth in Brazil in 2015. Univariate and multivariate sensitivity analysis were per- formed. Results: Adult vaccination with VE of 82.6% and coverage of 40%, at price of US$7.01 per dose, and assum- ing herd protection would avoid 167 infant deaths by pertussis, saving 12,325 years of life and costing a total of US$105495891.61, from the health system perspective. The universal immunization would result in ICER of US$8459.13. The results were highly sensitive to disease incidence. Conclusions: The results suggest that universal adult vaccination with Tdap would not be a cost-effective intervention for preventing pertussis cases and deaths in infants in Brazil. Ó 2019 Elsevier Ltd. All rights reserved. https://doi.org/10.1016/j.vaccine.2019.09.100 0264-410X/Ó 2019 Elsevier Ltd. All rights reserved. Abbreviations: AE, adverse events; ICER, incremental cost-effectiveness ratio; IBGE, Brazilian Institute of Geography and Statistics (Instituto Brasileiro de Estatística e Geografia); IIER, Instituto de Infectologia Emílio Ribas; LYS, life year saved; MoH, Ministry of Health; NIP, National Immunization Program; R$, Brazilian Reais; SIH-SUS, Hospital Information System database; SINAN, Notifiable Diseases Information System (Sistema de Informação de Agravos de Notificação); SINASC, Live Birth Information System (Sistema de Informações sobre Nascidos Vivos); SP, São Paulo State; SUS, Sistema Único de Saúde; Td, tetanus – diphtheria vaccine; Tdap, reduced diphtheria toxoid, acellular pertussis vaccine; US$, United States Dollar; VE, Vaccine effectiveness. ⇑ Corresponding author at: Departamento de Medicina Preventiva, Faculdade de Medicina da Universidade de São Paulo, Av. Dr. Arnaldo, 455 2◦andar, sala 2228, CEP: 01246-903 São Paulo, SP, Brazil. E-mail addresses: edergatti@hotmail.com (E.G. Fernandes), ana.sartori@hc.fm.usp.br (A.M.C. Sartori), patricia.soarez@usp.br (P.C. de Soárez), amaku@vps.fmvz.usp.br (M. Amaku), razevedo@usp.br (R.S. de Azevedo Neto), hidutilh@usp.br (H.M.D. Novaes). Vaccine xxx (xxxx) xxx Contents lists available at ScienceDirect Vaccine journal homepage: www.elsevier.com/locate/vaccine Please cite this article as: E. G. Fernandes, A. M. C. Sartori, P. C. de Soárez et al., Cost-effectiveness analysis of universal adult immunization with tetanus- diphtheria-acellular pertussis vaccine (Tdap) versus current practice in Brazil, Vaccine, https://doi.org/10.1016/j.vaccine.2019.09.100