Inequalities in complete pneumococcal vaccination among Peruvian children before and after the COVID-19 pandemic: An evaluation using demographic and health surveys from 2018 to 2023

To assess changes in complete pneumococcal vaccination coverage (CPVC) among Peruvian children <5 years before and after COVID-19 pandemic and to evaluate regional and other associated factors as well as wealth-related inequality. This retrospective study analyzed data from the demographic and health surveys (DHS) 2018-2023. CPVC was defined as having received the complete vaccination schedule (2+1 dose) of the 13-valent pneumococcal vaccine (PCV13). Children aged 13-60 months were included. Modified Poisson regression was performed for multivariable analysis. Wealth-related inequality was assessed using the Concentration index and Erreygers’s corrected Concentration index at national and regional levels. Among 95,586 children, CPVC declined from 71.9% in 2019 to 69.4% in 2020 (p=0.003), then returned to pre-Covid levels from 2021 onwards (72.2% in 2023; p=0.001), particularly in Lima Metropolitana. Puno (53.3- 58.6%) and Madre de Dios (50.9-62.1%) consistently showed the lowest coverage. Nationally, no clear evidence showed that sociodemographic or economic inequality affected coverage, with minimal effect sizes. However, interaction was identified between regions and wealth, modifying the effect on CPVC. Depending on the region, variables such as age group, household members and mother’s education were associated with lower CPVC, whereas age at first pregnancy, birth in a health facility, antenatal care and access information were associated with higher CPVC. These associations differed in magnitude by region. Ucayali showed persistently higher CPVC among wealthier populations. Despite a temporary decline during the pandemic, Peru’s CPVC rapidly recovered and remained high. Regional inequality persist, particularly in southern jungle areas. Targeted strategies are recommended to improve CPVC in populations with persistently low coverage.