Vaccination coverage against flu: advances, challenges and inequalities by autonomous communities in Spain...

To evaluate the vaccination coverage against seasonal influenza in Spain between 2019 and 2023, analyzing trends by population groups, autonomous communities and factors associated with temporal and contextual variations.

Retrospective longitudinal study using data from the Vaccine Information System (SIVAMIN). Coverage was analyzed in the following groups: children (6-59 months), adults (60-64, 65-74, >74 years), pregnant women and health personnel. Coverage was calculated as the percentage of vaccinated patients with respect to the susceptible population and a descriptive and regression analysis was performed to evaluate temporal trends.

Between 2019 and 2023, those over 74 years of age maintained high coverage (>73%), with slight decreases. In the 65-74 age group, coverage was good but uneven across regions. In adults aged 60-64 years and pregnant women, a post-pandemic decline was observed. Coverage in health professionals fell markedly (from 66% to 44%). In children aged 6-59 months, incorporated in 2023, coverage was 36%, with marked regional disparities.

Vaccination coverage shows persistent progress and challenges, with significant inequalities by autonomous communities. Those over 74 years of age and pregnant women have maintained relatively high rates, reflecting campaigns aimed at these vulnerable groups. The pandemic boosted occasional coverage, but the trend was not sustained. Sustainable strategies are required to improve equity and maintain confidence in vaccination, especially in key groups such as children, health care providers, and by autonomous communities with less access.