Missed opportunities for vaccination in Peru 2010-2020: A study of socioeconomic inequalities

Abstract

Background: Missed Opportunities for Vaccination (MOV) represent a major risk in the re-emergence of immunopreventable diseases. However, in the region, there are few published studies on MOVs using national databases such as demographic and health surveys (DHS). This study aims to describe the frequency and trends of MOVs for the first dose of vaccines against the leading causes of infant morbidity and mortality, their complete vaccination coverage, and trends in socioeconomic inequalities at the national and departmental levels for an 11-years period.

Methods: Using DHS data from an 11-year period (2010-2020), we calculated frequencies and trends in MOVs of vaccines for the leading causes of child morbidity and mortality, estimated inequalities in MOVs using the Slope Inequality Index (SII) and conducted a spatial autocorrelation test to identify clusters of higher or lower inequality in MOVs at the national level.

Findings: We found that, at the national level, greater inequality was concentrated in the wealthiest categories of each socioeconomic variable. We identified that departments with higher poverty rates concentrated higher levels of inequality in the MOVs in the lowest strata of the socioeconomic variables. In addition, we found that some departments with similar geographic and socioeconomic characteristics had spatially correlated levels of inequality on MOVs.

Interpretation: These findings can help to identify the heterogeneity that exists in the distribution of MOVs among departments and socioeconomic strata, which would help to prioritize specific areas and subpopulations for national immunization strategies.

Funding: No additional funding source was required for this study.

Keywords: Demographic and health survey; Healthcare disparities; Immunization; Immunization programs; Socioeconomic factors; Vaccines.

Figure 1

Vaccination coverage 2010-2020. Coverage of the first doses of pentavalent (PTV), Pneumococcal (NEUMO), Influenza (INLFU and Rotavirus vaccine (ROTA). The dashed line indicates the start of the new sampling methodology.

Figure 2

Distribution of complete doses of vaccine. a. Doses completes of four vaccines for under five years calculated with the unweighted population of the 11 years. b. Complete vaccination schedule for each vaccine by department.

Figure 3

Evolution of MOVs for each vaccine during the 11-years period. MOVs of pentavalent (PTV), Pneumococcal (NM), Influenza (INLFU) and Rotavirus vaccine (ROTA). The dashed line indicates the start of the new sampling methodology.

Figure 4

Slope Index of Inequality at national level for the four vaccines. a. Maternal Education. b. Wealth index. Evolution of SII of the four vaccines during the 11 years at national level and Moran's I test results. A heatmap is shown with the results per year and per vaccine with Moran's I test estimates (top). Estimates with non-significant p-values are transparent. The evolution of SII for each vaccine during the 11 years is shown with its CI (bottom). The shaded area indicates the start of the new sampling methodology.

Figure 5

Slope Index of Inequality of the MOVs for each department from 2010 to 2020 (Wealth index, WI). The 4 years are shown as a reference of SII variations during the 11 years of study. A. INFLU, B. PNEUMO, C. PTV, D. ROTA. Abbreviations of departments in Supplementary Table 2.

Figure 6

Slope Index of Inequality of the MOVs for each department from 2010 to 2020 (Maternal Education, ME). The 4 years are shown as a reference of SII variations during the 11 years of study. A. INFLU, B. PNEUMO, C. PTV, D. ROTA. Abbreviations of departments in Supplementary Table 2.

Figure 7

Stratification of the Slope Index of Inequality analysis. and B. Stratification by access and non-access to the JUNTOS program, respectively. C and D. Stratification by housing in rural and urban areas, respectively. E and F. Stratification by CRED care in a government and private facility, respectively. WI: Wealth index. ME: Maternal Education. The shaded area indicates the start of the new sampling methodology.