Disease and Economic Burden Averted by Hib Vaccination in 160 Countries: A Machine-Learning Analysis.

Area of Science:

• Global Health
• Vaccinology
• Health Economics

Background:

• Haemophilus influenzae type b (Hib) immunization programs have expanded globally, supported by Gavi.
• This study assesses the health, economic, equity, and cost-effectiveness impacts of Hib vaccination in 159 countries from 1990-2021.
• Future projections for Hib vaccine introduction in China are also analyzed.

Purpose of the Study:

• To estimate the global health and economic benefits of Haemophilus influenzae type b (Hib) immunization.
• To evaluate the equity and cost-effectiveness of Hib vaccination programs.
• To project the impact of future Hib vaccine introduction in China.

Main Methods:

• A random forest model was employed to simulate counterfactual scenarios without Hib vaccine.
• Data from the World Bank, WHO, and the Global Burden of Disease Study 2021 were utilized.
• Benefits, equity, and cost-effectiveness were quantified by comparing counterfactual and actual outcomes, with extensive uncertainty analyses.

Main Results:

• Hib immunization averted over 1.3 million deaths and 91 million disability-adjusted life-years globally between 1990 and 2021.
• The greatest health and economic benefits were observed in Africa and low- and middle-income countries (LMICs).
• Hib immunization was cost-saving in all analyzed countries, though it did not improve health equity due to persistent access limitations in LMICs.

Conclusions:

• Haemophilus influenzae type b (Hib) immunization offers substantial and cost-effective global health and economic advantages.
• Addressing persistent inequities in vaccine access for LMICs is crucial for equitable global health outcomes.
• Findings provide evidence for policymakers in China regarding the benefits of future Hib vaccine introduction.