Medicine
Cost-Effectiveness Analysis of Vaccination Programs
Quick fact
A study of childhood vaccines in low- and middle-income countries found that every dollar spent on vaccination could return up to $44 in economic benefits, highlighting their exceptional cost-effectiveness.
Why this is interesting
Why do some vaccines, like the HPV vaccine, seem to have a high price tag, yet are still considered some of the best investments in public health?
Read the full explanation
Understanding Cost-Effectiveness Analysis of Vaccination Programs
Cost-effectiveness analysis (CEA) is a way to compare the costs and health outcomes of a vaccination program against an alternative, such as doing nothing or using a different vaccine. Think of it like shopping for groceries: you want the best health 'bang' for your buck. The main outcome is often expressed as cost per quality-adjusted life year (QALY) gained. A QALY is a measure that combines both the quantity and quality of life—one QALY equals one year in perfect health. For example, if a vaccine costs $500 and prevents an illness that would have taken away 0.1 QALY, the cost per QALY gained would be $5,000. Policymakers compare this to a willingness-to-pay threshold (e.g., $50,000 per QALY in many countries) to decide if it's worth funding. This framework is used globally to prioritize vaccines, especially when resources are limited.
A deeper explanation
The mechanism of CEA begins with defining a perspective—whether we count only healthcare costs (like hospitalizations and treatments) or also indirect costs such as lost work productivity. Then, we model the disease without vaccination and with vaccination, tracking outcomes like infections, complications, and deaths. The key output is the incremental cost-effectiveness ratio (ICER), which is the difference in costs divided by the difference in health outcomes (usually QALYs) between the two scenarios. Mathematically, ICER = (Costvaccine - Costnovaccine) / (QALYvaccine - QALYnovaccine). A lower ICER means the vaccine is more cost-effective. Because benefits like immunity and prevention of future disease occur over years, future costs and QALYs are discounted (e.g., at 3% per year) to reflect time preference. Sensitivity analysis then tests how robust the results are under varying assumptions (e.g., vaccine efficacy, disease transmission). This systematic comparison reveals that even expensive vaccines can be cost-effective because they prevent costly hospitalizations and long-term disability, and because they contribute to herd immunity, which protects unvaccinated people. This is why CEA has become a cornerstone of health technology assessment for national immunization programs.