Bridging the Gap: Two Decades of Childhood Vaccination Coverage and Equity in Cambodia and the Philippines (2000-2022).

Equitable access to childhood vaccines remains a challenge in many low- and middle-income countries. This study assessed coverage of WHO-recommended childhood vaccines in Cambodia and the Philippines, focusing on urban-rural and wealth disparities, and examined maternal demographic and socioeconomic factors influencing vaccination coverage. Cross-sectional data from Demographic and Health Surveys from Cambodia (2000-2021/22) and the Philippines (2003-2022) were used. Descriptive analyses were performed to elucidate vaccination coverage trends (BCG, hepatitis B birth dose, DTP, OPV, PCV, and measles). Urban-rural and wealth-related disparities were assessed by calculating absolute differences and Slope Index of Inequality. Logistic regression was used to analyze the impact of maternal demographics and socioeconomic status on vaccination coverage. Cambodia showed significant increases in BCG, DTP, and OPV coverage over the past two decades, whereas those coverage in the Philippines declined slightly since 2017. In 2022, 75.2% of Filipino children received the BCG and hepatitis B (birth dose) vaccines, and around two-thirds completed DTP, OPV, and PCV vaccinations on schedule, lower than the rates in Cambodia. Only half of the children completed measles vaccination in both countries. Urban-rural disparities declined over time in both countries, but wealth inequalities persisted and widened in the Philippines between 2017 and 2022. Women with higher education attainment, from a wealthy household and having fewer children, was associated with increased likelihood of completing childhood vaccinations in both countries. Persistent socioeconomic disparities in childhood vaccination in low- and middle-income countries highlight the need for targeted pro-poor and community-based strategies to ensure equitable access.