An investigation into ethnic group and deprivation inequalities in influenza and COVID-19 hospitalizations, post-pandemic

Health system decision-makers need evidence on how modifiable factors contribute to inequalities to inform effective interventions. We examined ethnic group and deprivation inequalities in influenza and COVID-19 hospitalizations in England (2023 - 2024) among vaccine-eligible individuals, using causal mediation analysis to assess the roles of deprivation, vaccination uptake and comorbidities. For influenza, hospitalization odds were highest among Pakistani and Bangladeshi groups, compared with White British individuals (OR 2.0, 95% CI: 1.83, 2.10; OR 1.6, 95% CI: 1.39, 1.80, respectively). Deprivation mediated 26% of the total ethnic group effect for the Pakistani group and 41% for the Bangladeshi group, whilst comorbidities contributed little. Ethnic group differences in COVID-19 hospitalizations were minimal in this post-pandemic period. For both infections, the most deprived group had disproportionately high hospitalization compared to the least deprived (influenza OR 1.7, 95% CI: 1.63, 1.79; COVID-19 OR 1.5, 95% CI: 1.43, 1.55. For influenza, vaccination uptake mediated 17-26% of deprivation effects, whilst for COVID-19, there were no meaningful residual deprivation inequalities after including vaccination uptake and comorbidities. Vaccination uptake and deprivation mediate a substantial proportion of inequalities in hospitalization for influenza and COVID-19 in the vaccine-eligible cohort. Improving vaccination coverage in under-vaccinated groups should remain a public health priority.