Vaccine Attitudes Among Adults in a Southern European Region: Survey from Pre- to Post-COVID-19

Vaccine hesitancy and refusal are growing public health challenges, reflecting individual decisions and social inequalities. The COVID-19 pandemic reshaped vaccine perceptions and may have amplified pre-existing differences. This study analyzed the evolution of vaccine hesitancy and refusal among adults in the Community of Madrid (Spain) between 2019 and 2024. We also explored the associated sociodemographic profiles.

A retrospective observational study was conducted using data from the Non-communicable Disease Risk-Factor Surveillance System through a computer-assisted telephone interview (CATI) survey, targeting adults aged 18-64 years. Four waves (2019, 2020, 2021, 2024) were analyzed. Prevalence rates with 95% confidence intervals (95%CI) were calculated. The associations with sociodemographic variables (sex, age, country of birth, education, and employment status) were assessed using Poisson regression models to obtain crude and adjusted prevalence ratios (aPR).

A total of 7978 participants were included (49.1% men; mean age 41.97 years). Vaccine hesitancy increased from 3.8% (95% CI: 3.0-4.7) in 2019 to 18.5% (95% CI: 16.8-20.2) in 2024; vaccine refusal increased from 2.1% (95% CI: 1.6-2.8) to 8.0% (95% CI: 6.9-9.3). Vaccine hesitancy and refusal adjusted for socioeconomic variables increased in 2024 compared to 2019 (PRa: 5.04; 95% CI: 3.96-6.41 and aPR: 4.00; 95% CI: 2.86-5.59, respectively). Hesitancy was associated with female sex and middle age in 2019, to middle age in 2020, to intermediate education and migrant origin in 2021, and to education and migrant status in 2024. Vaccine refusal showed a similar pattern to that of vaccine hesitancy, highlighting the association with socioeconomic vulnerability.

Between 2019 and 2024, vaccine hesitancy and refusal increased, and the association with socioeconomic vulnerability has also increased. Equity-based vaccination strategies are needed in order to strengthen institutional trust and reduce structural barriers to vaccine acceptance.