ABSTRACT
Background: Vaccination is one of the most effective ways of preventing and controlling influenza, while seasonal influenza vaccine has not been introduced to China’ National Immunization Program (NIP). To inform immunization policy-making in China, this study aims to assess the cost-effectiveness of introducing influenza vaccination in China’s NIP for children aged 6-59 months.
Methods: We performed a cost-effectiveness analysis based on a decision-tree Markov model to estimate the impact of influenza vaccination in NIP on the disease burden, quality-adjusted life years (QALYs) and disease costs for influenza-affected young children in China. The analysis adopted a societal perspective in a lifetime time horizon. The immunization schedule for children was given special consideration, including the recommended two-dose vaccination for children aged under eight who were vaccinated for the first time, and the differentiated vaccine dosage (0.25ml or 0.5ml) for children aged less or more than three. All costs were discounted at 3% and reported in 2017 US dollars (US$ 1=6.8 CNY), adjusting for inflation if necessary. Cases and deaths averted, QALYs gained and incremental cost-effectiveness ratios (ICER) were estimated to compare the status quo and NIP scenarios. The incremental cost per QALYs gained was compared with the 2017 GDP per capita (US$ 8 818) and three times the GDP per capita (US$ 26 453). Univariate and probabilistic sensitivity analyses were performed to test the robustness of results and assess the sources of uncertainty.
Results: The introduction of influenza vaccination in China’s NIP could avert approximately 17.5% (126 412 cases and 353 deaths) of influenza disease within a single birth cohort at the national level. The ICERs per case averted, per death averted, and per QALY gained were US$ 2 318, US$ 829 026, and US$ 27 620, respectively. The ICER per QALY gained was less than three times the 2017 GDP per capita (US$ 26 453), indicating that introducing influenza vaccination in China’s NIP was not estimated to be cost-effective for this target-group. Sensitivity analyses revealed that the most important parameters were the incidence of influenza and the costs of vaccination.
Conclusion: This study is the first in China to assess the cost-effectiveness of influenza vaccination for young children from the societal perspective. Introducing influenza vaccination in China’s NIP seems not cost-effective nationally, so step-by-step measures were recommended to inform policies on expanding influenza vaccination coverage in China. The model is useful in identifying key elements for economic evaluation of influenza vaccines, and in future studies, more accurate data are required to increase the reliability of the results.