Targeted Influenza Vaccination in at Risk Populations – How Avoided Cases Translate into Clinical and Economic Benefits for Czech Republic, Hungary, and Romania

OBJECTIVES: The World Health Organization(WHO) has urged European countries to reach 75% influenza vaccination coverage rate(VCR) in vulnerable populations (older adults, patients with comorbidities[PwC], children aged 6-24 months, healthcare workers[HCW], and pregnant women[PW]). We assessed the additional clinical and economic benefits of reaching suggested VCR in three selected countries.

METHODS: A decision analytic model, capturing 2021/2022 epidemiologic inputs (for each subgroup: eligible population, VCR, influenza attack rates, quadrivalent influenza vaccine efficacy) and 2022 costs expressed in euros (direct medical costs of influenza-related physician consultations and hospitalizations) was built. For selected countries (Czech Republic[CZ], Hungary[HU] and Romania[RO]), a one-year comparison of observed vs 75% VCR in terms of influenza cases avoided and costs informed the potential benefits of reaching WHO recommendation (expressed in thousands[K]). Local inputs and robust, published sources were prioritized.

RESULTS: Country-average observed VCR were 22.4%, 20.27%, 1.5%, 19% and 1.83% for older adults, PwC, children, HCW, and PW. Older adults consistently displayed the highest clinical benefit of reaching 75% VCR (47.9K up to 86.5K additional averted influenza cases for CZ and RO, respectively), followed by PwC and children. Additional averted hospitalizations and physician visits ranged from 1.8K for CZ up to 3.4K for RO, and 15.7K for CZ up to 34.1K for HU, respectively. Averted influenza cases translate into additional savings of 1.268K € for HU, 1.866K € for CZ and 2.929K € for RO in costs; hospitalizations average 68% (49%[HU] to 81%[RO]) of those spared monetary resources.

CONCLUSIONS: A punctual objective to increase VCR up to 75% in vulnerable populations can avert influenza cases and its related clinical and economic consequences, reducing the burden of disease for CZ, HU and RO. Older adults will mostly benefit from such a policy, future research focused on enhanced influenza vaccines for this population might accentuate the importance of these findings.