Methods and challenges for the health impact assessment of vaccination programs in Latin America

Abstract

OBJECTIVE To describe methods and challenges faced in the health impact assessment of vaccination programs, focusing on the pneumococcal conjugate and rotavirus vaccines in Latin America and the Caribbean.METHODS For this narrative review, we searched for the terms “rotavirus”, “pneumococcal”, “conjugate vaccine”, “vaccination”, “program”, and “impact” in the databases Medline and LILACS. The search was extended to the grey literature in Google Scholar. No limits were defined for publication year. Original articles on the health impact assessment of pneumococcal and rotavirus vaccination programs in Latin America and the Caribbean in English, Spanish or Portuguese were included.RESULTS We identified 207 articles. After removing duplicates and assessing eligibility, we reviewed 33 studies, 25 focusing on rotavirus and eight on pneumococcal vaccination programs. The most frequent studies were ecological, with time series analysis or comparing pre- and post-vaccination periods. The main data sources were: health information systems; population-, sentinel- or laboratory-based surveillance systems; statistics reports; and medical records from one or few health care services. Few studies used primary data. Hospitalization and death were the main outcomes assessed.CONCLUSIONS Over the last years, a significant number of health impact assessments of pneumococcal and rotavirus vaccination programs have been conducted in Latin America and the Caribbean. These studies were carried out few years after the programs were implemented, meet the basic methodological requirements and suggest positive health impact. Future assessments should consider methodological issues and challenges arisen in these first studies conducted in the region.

Impact and Effectiveness of 10 and 13-Valent Pneumococcal Conjugate Vaccines on Hospitalization and Mortality in Children Aged Less than 5 Years in Latin American Countries: A Systematic Review

“…As reported in the literature [65], our results shows that most studies on impact of public health interventions used secondary data from health information systems, surveillance systems, and others sources, while few studies used primary data. As hospitalization and mortality outcomes are the most relevant outcomes of interest, it is expected that secondary data are the most used data sources.…”

“…On the other hand, effectiveness measurements based on observational study designs, such as cohort and case-control studies, estimated the proportion of cases prevented in vaccinated subjects that were attributable to vaccination excluding indirect effects. A recent study describing methods and challenges for impact assessment of vaccination in LAC region reported a significant increase in the number of studies on pneumococcal vaccine impact [65]. As other authors have reported in developed countries [64], several are the methodological challenges faced when assessing vaccination impact, particularly considering PCV.…”

Effectiveness and impact of the 10-valent pneumococcal conjugate vaccine, PHiD-CV: review of clinical trials and post-marketing experience

“…The impact of PHiD-CV against IPD has also been estimated in Brazil, Chile, and Colombia using data collected by the Latin American laboratory network for passive surveillance of bacterial pneumonia and meningitis pathogens (SIREVA II) [16]. While these data provide useful information on serotype distribution during particular periods of time, caution is advised in the analysis of the impact of vaccination since SIREVA II is a voluntary system and completeness of reporting varies among countries [17]. Analyses of the laboratory-based data are also limited by a lack of demographic and clinical information.…”

Countering vaccine hesitancy through immunization information systems, a narrative review

“…160 The use of IIS is a promising tool useful for both vaccine providers and vaccine recipients as well as public health policy makers and epidemiologists. 13,161 It allows access to flexible analyses that cannot be done using other vaccination data sources. It is able to reduce the burden of manual paper reporting systems, to facilitate quarterly vaccine coverage reports instead of aggregate data, to increase the accuracy of the data and to track the administered doses.…”