ABSTRACT
Objectives: Pertussis, a highly contagious respiratory disease caused by Bordetella pertussis, is endemic in Brazil, but is underdiagnosed in adults due to atypical symptomatology and limited diagnosis time window. Brazil's Ministry of Health recommends decennial boosters in adults against diphtheria and tetanus, but not pertussis. After the COVID-19 pandemic, infectious diseases surged worldwide due to lack of natural exposure and reduced immunization coverage. Asthma and COPD populations are at increased risk of pertussis infection. This study assessed the cost-utility of decennial pertussis vaccination with Tdap vaccine versus no pertussis vaccination in Brazil's adult asthma and COPD populations in a high-incidence context. Method(s): A static cross-sectional population-based cost-utility model of decennial Tdap boosters in asthma patients >=50 years and COPD patients >=40 years was developed from the payer's perspective. Pertussis incidence from Sao Paulo's state surveillance system in the peak year 2014 was adjusted for underdiagnosis and relative risk of pertussis in asthma and COPD populations. Vaccine efficacy and coverage, and costs and outcomes discounted at 5%, were obtained from the literature and public databases. Deterministic and probabilistic sensitivity analyses, and scenario analyses were run, including alternative annual incidence. Result(s): In the asthma population, Tdap boosters would incur 7,065,788 Brazilian reais (BRL) direct costs and save 32.85 Life Years (LYs) and 262.13 Quality-Adjusted LYs (QALYs). In the COPD population, Tdap boosters would incur 41,102,844 BRL direct costs and save 157.47 LYs and 1,078.26 QALYs. Discounted incremental cost-utility ratios were 26,956 and 38,120 BRL/QALY in asthma and COPD populations, respectively. At a cost-effectiveness threshold of 1 Gross Domestic Product (GDP)/capita, 85.8% and 49.7% of simulations were cost-effective in asthma and COPD populations, respectively, while all simulations were cost-effective at a threshold of 3 GDP/capita. Conclusion(s): Implementing decennial Tdap boosters for adult asthma and COPD patients should be considered, given the favorable cost-utility profile in peak-incidence years.Copyright © 2023