Tends of "Zero-dose" children aged 12-23 months in Togo from 2000 to 2017 and predictions for 2030

Guided by the principle of leaving no one behind by improving equitable access and use of new and existing vaccines, the Immunization Agenda 2030 aims, among other things, to halve the incidence of "zero-dose" at the national level. This study aimed at studying the tends of the prevalence of "zerodose" children from 2000 to 2017 and making predictions for 2030. The study consisted of secondary data analyses from the Multiple Indicator Cluster Surveys (MICS) conducted in Togo. The study population consisted of children aged 12-23 months surveyed during MICS2 in 2000, MICS3 in 2006, MICS4 in 2010 and MICS6 in 2017. The dependent variable was the "zero-dose" vaccination status (1=Yes vs 0=No). The explanatory variables were related to the child, mother, household and environment. The study generated the overall annual percentage changes (APC) and by the independent variables. As a result, the prevalence of children with "zero-dose" expected for 2030 was estimated using Excel 2013 and Stata 16.0 software. In total, 636, 864, 916 and 952 children aged 12-23 months were included for MICS2, MICS3, MICS4 and MICS7, respectively. The prevalence of "zerodose" children decreased from 37.15% in 2000 to 31.72% in 2006, then 30.10% in 2010 and 26.86% in 2017, with an overall APC= - 1.89%. The highest relative annual decrease was from 2000 to 2006. If the historical rate of decrease remains unchanged, we predict that percentage of "zero-dose" children aged 12-23 months will be 20.96% in 2030, with a decrease of 22% compared to 2017, against a target of 50%. We suggest that strengthening strategies to increase full immunization coverage of children will contribute to reducing the percentage of zero dose children. A prerequisite will be a better understanding of the predictors of the "zero-dose" phenomenon in children

Preplanned national measles vaccination campaign at the beginning of a measles outbreak--Sierra Leone, 2009-2010.

BACKGROUND: Large-scale measles outbreaks occurred throughout Africa from 2008-2010. In Sierra Leone, in November 2009, preceding a measles supplemental immunization activity (SIA), the largest measles outbreak in a decade started. METHODS: We analyzed data from the national measles case-based surveillance system, developed a susceptibility profile of the population, and calculated vaccine effectiveness (VE) among children 12-59 months of age. RESULTS: From November 1, 2009 to July 13, 2010, 1,094 confirmed cases, including 9 deaths, were reported; 716 (66%) were <5 years of age. B3 genotype was identified. Measles attack rates per 100,000 population were highest among infants aged 6-8 months (56.4) and in Bo district (49.4). Districts with higher estimated SIA coverage tended to have lower attack rates (Spearman Correlation Coefficient=-0.63), p=0.07. Among 473 cases with information on vaccination status, 222 (47%) were unvaccinated; estimated VE was 74%. The 2009 measles SIA led to 165,000 fewer estimated susceptible individuals. CONCLUSIONS: The 2009 measles SIA reduced the overall magnitude of the outbreak, though routine and SIA coverage was insufficient to prevent it entirely. Maintaining high coverage through routine services and SIAs in all districts and conducting follow-up SIAs prior to the end of the low transmission season may prevent future outbreaks.