Burden of Influenza and Cost-Effectiveness Analysis of Introduction of an Influenza Vaccination Programme Among Older Adults in India

This peer-reviewed article assesses the burden of influenza and the cost-effectiveness of introducing a seasonal influenza vaccination programme for older adults in India. Using data from the Indian Network of Population-Based Surveillance Platforms for Influenza and Other Respiratory Viruses among the Elderly (INSPIRE), the study combined three years of community cohort and hospital surveillance data with a decision-analytic model to estimate influenza-related morbidity, mortality, disability-adjusted life years (DALYs), costs, and the economic impact of vaccination strategies among adults aged ≥60 years. 

Key findings

• The study estimated that influenza causes approximately 5.3 million symptomatic acute respiratory infections annually among adults aged ≥60 years in India.
• Influenza among older adults was estimated to result in around 36,000 hospitalizations, 16,700 ICU admissions, and 84,600 deaths each year.
• Influenza-associated illness among older adults accounted for an estimated 974,019 DALYs lost annually in India.
• The annual economic burden of influenza in this population was estimated at US$66.6 million in 2021, excluding productivity losses due to premature mortality.
• More than half (54%) of the economic burden was attributable to severe illness requiring hospitalization or ICU care.
• Compared with no vaccination, both facility-based and outreach-based influenza vaccination strategies for adults aged ≥60 years were estimated to be cost-effective using India’s 2021 GDP per capita as the cost-effectiveness threshold.
• The incremental cost-effectiveness ratio (ICER) was estimated at US$1979 per DALY averted for a facility-based strategy and US$1851 per DALY averted for an outreach-based strategy.
• Vaccinating adults aged ≥60 years with specified comorbidities was identified as the most cost-effective strategy and the option with the lowest budgetary impact.
• Sensitivity analyses showed that results were most influenced by influenza incidence, vaccine delivery costs, and vaccine effectiveness.
• The probabilistic sensitivity analysis found that around 70% of simulations remained below the selected cost-effectiveness threshold, supporting the robustness of the findings.

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