Marta Gacic-dobo - Academia.edu (original) (raw)

Papers by Marta Gacic-dobo

In 2002, the UN General Assembly Special Session on Children adopted a goal to reduce deaths owin... more In 2002, the UN General Assembly Special Session on Children adopted a goal to reduce deaths owing to measles by half by the end of 2005, compared with 1999 estimates. We describe efforts and progress made towards this goal. Methods We assessed trends in immunization against measles on the basis of national implementation of the WHO/UNICEF comprehensive strategy for measles mortality reduction, and the provision of a second opportunity for measles immunization. We used a natural history model to evaluate trends in mortality due to measles. Results

Releve epidemiologique hebdomadaire, 2016

In 2010, the World Health Assembly set 3 milestones for measles prevention to be achieved by 2015... more In 2010, the World Health Assembly set 3 milestones for measles prevention to be achieved by 2015: 1) increase routine coverage with the first dose of measlescontaining vaccine (MCV1) among children aged 1 year to ≥90% the national level and to ≥80% in every district; 2) reduce global annual measles incidence to <5 cases per million population; and 3) reduce global measles mortality by 95% from the 2000 estimate.1, 2 In 2012, the Assembly endorsed the Global Vaccine Action Plan (GVAP),3 with the objective of eliminating measles4 in 4 of the 6 WHO regions by 2015 and in 5 regions by 2020. Countries in all 6 WHO regions have adopted goals for measles elimination by 2020. This report describes progress towards global measles control and regional measles elimination goals during 2000–2017 and updates a previous report.5 During 2000–2017, estimated MCV1 coverage increased globally from 72% to 85%; annual reported measles incidence

Background : The objective of the study was to assess compliance of the WHO and UNICEF estimates ... more Background : The objective of the study was to assess compliance of the WHO and UNICEF estimates of national immunization coverage (WUENIC) against the 18 criteria of the Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER) that define and promote good practice in reporting of global health estimates. Methods : We conducted a desk review of the WUENIC estimation and reporting process vis-a-vis each of the 18 GATHER criteria to complete a self-assessment of compliance with GATHER. Results : Overall, WUENIC estimates are fully compliant with 17 of the GATHER criteria and partially compliant with one criterion—criterion 11, which is related to candidate model evaluation and final model selection. Conclusion : The GATHER criteria provide a useful framework for documenting WUENIC’s compliance with contemporary reporting requirements. Given the role of vaccination coverage estimates in global monitoring and guiding disease control efforts, WHO and UNICEF strive to p...

Preventive Medicine, 2021

WHO/UNICEF estimates for HPV vaccination coverage from 2010 to 2019 are analyzed against the back... more WHO/UNICEF estimates for HPV vaccination coverage from 2010 to 2019 are analyzed against the backdrop of the 90% coverage target for HPV vaccination by 2030 set in the recently approved global strategy for cervical cancer elimination as a public health problem. As of June 2020, 107 (55%) of the 194 WHO Member States have introduced HPV vaccination. The Americas and Europe are by far the WHO regions with the most introductions, 85% and 77% of their countries having already introduced respectively. A record number of introductions was observed in 2019, most of which in lowand middle-income countries (LMIC) where access has been limited. Programs had an average performance coverage of around 67% for the first dose and 53% for the final dose of HPV. LMICs performed on average better than high-income countries for the first dose, but worse for the last dose due to higher dropout. Only 5 (6%) countries achieved coverages with the final dose of more than 90%, 22 countries (21%) achieved coverages of 75% or higher while 35 (40%) had a final dose coverage of 50% or less. When expressed as world population coverage (i.e., weighted by population size), global coverage of the final HPV dose for 2019 is estimated at 15%. There is a long way to go to meet the 2030 elimination target of 90%. In the post-COVID era attention should be paid to maintain the pace of introductions, specially ensuring the most populous countries introduce, and further improving program performance globally.

MMWR. Morbidity and Mortality Weekly Report, 2019

PLOS ONE, 2019

Background A common means of vaccination coverage measurement is the administrative method, done ... more Background A common means of vaccination coverage measurement is the administrative method, done by dividing the aggregated number of doses administered over a set period (numerator) by the target population (denominator). To assess the quality of national target populations, we defined nine potential denominator data inconsistencies or flags that would warrant further exploration and examination of data reported by Member States to the World Health Organization (WHO) and UNICEF between 2000 and 2016. Methods and findings We used the denominator reported to calculate national coverage for BCG, a tuberculosis vaccine, and for the third dose of diphtheria-tetanus-pertussis-containing (DTP3) vaccines, usually live births (LB) and surviving infants (SI), respectively. Out of 2,565 possible reporting events (data points for countries using administrative coverage with the vaccine in the schedule and year) for BCG and 2,939 possible reporting events for DTP3, 194 and 274 reporting events were missing, respectively. Reported coverage exceeding 100% was seen in 11% of all reporting events for BCG and in 6% for DTP3. Of all year-to-year percent differences in reported denominators, 12% and 11% exceeded 10% for reported LB and SI, respectively. The implied infant mortality rate, based on the country's reported LB and SI, would be negative in 9% of all reporting events i.e., the country reported more SI than LB for the same year. Overall, reported LB and SI tended to be lower than the UN Population Division 2017 estimates, which would lead to overestimation of coverage, but this difference seems to be decreasing over time. Other inconsistencies were identified using the nine proposed criteria.

MMWR. Morbidity and Mortality Weekly Report, 2018

Endorsed by the World Health Assembly in 2012, the Global Vaccine Action Plan 2011-2020 (GVAP) (1... more Endorsed by the World Health Assembly in 2012, the Global Vaccine Action Plan 2011-2020 (GVAP) (1) calls on all countries to reach ≥90% national coverage with all vaccines in the country's national immunization schedule by 2020. This report updates previous reports (2,3) and presents global, regional, and national vaccination coverage estimates and trends as of 2017. It also describes the number of infants surviving to age 1 year (surviving infants) who did not receive the third dose of diphtheria and tetanus toxoids and pertussis-containing vaccine (DTP3), a key indicator of immunization program performance (4,5), with a focus on the countries with the highest number of children who did not receive DTP3 in 2017. Based on the World Health Organization (WHO) and United Nations Children's Fund (UNICEF) estimates, global DTP3 coverage increased from 79% in 2007 to 84% in 2010, and has remained stable from 2010 to 2017 (84% to 85%). In 2017, among the 19.9 million children who did not receive DTP3 in the first year of life, 62% (12.4 million) lived in 10 countries. From 2007 to 2017, the number of children who had not received DTP3 decreased in five of these 10 countries and remained stable or increased in the other five. Similar to DTP3 coverage, global coverage with the first measles-containing vaccine dose (MCV1) increased from 80% in 2007 to 84% in 2010, and has remained stable from 2010 to 2017 (84% to 85%). Coverage with the third dose of polio vaccine (Pol3) has remained stable at 84%-85% since 2010. From 2007 to 2017, estimated global coverage with the second MCV dose (MCV2) increased from 33% to 67%, as did coverage with the completed series of rotavirus (2% to 28%), pneumococcal conjugate (PCV) (4% to 44%), rubella (26% to 52%), Haemophilus influenzae type b (Hib) (25% to 72%) and hepatitis B (HepB) (birth dose: 24% to 43%; 3-dose series: 63% to 84%) vaccines. Targeted, context-specific strategies are needed to reach and sustain high vaccination coverage, particularly in countries with the highest number of unvaccinated children. In 1974, WHO established the Expanded Program on Immunization (EPI) to ensure that all children have access to four routinely recommended vaccines that protect against tuberculosis, diphtheria, tetanus, pertussis, polio, and measles (4): bacillus Calmette-Guérin vaccine (BCG), DTP, polio vaccine (Pol), and MCV. WHO and UNICEF derive national coverage estimates through an annual country-by-country review of all available data, including administrative and survey-based coverage (5,6); in general, only doses administered through routine immunization

Vaccine, Aug 21, 2018

Household surveys are frequently used as means of vaccination coverage measurement, but obtaining... more Household surveys are frequently used as means of vaccination coverage measurement, but obtaining accurate survey estimates present several challenges. In 2015, the World Health Organization (WHO) released a working draft of its updated Vaccination Coverage Survey Reference Manual that moved well beyond the traditional Expanded Program on Immunization (EPI) survey design. In April 2017, WHO convened a four-day meeting, to review lessons learned using the updated manual and to define an agenda for operational research about vaccination coverage surveys. About 70 stakeholders, including EPI managers and participants from 10 countries that have used the updated Survey Manual, survey experts, statisticians, partners, representatives from WHO regional offices and headquarters, and providers of technical assistance discussed methodological issues from sampling to accurately ascertaining a person's vaccination status, optimizing data collection and data management and conducting approp...

MMWR. Morbidity and mortality weekly report, Jan 17, 2017

The Global Vaccine Action Plan 2011-2020 (GVAP) (1), endorsed by the World Health Assembly in 201... more The Global Vaccine Action Plan 2011-2020 (GVAP) (1), endorsed by the World Health Assembly in 2012, calls on all countries to reach ≥90% national coverage for all vaccines in the country's routine immunization schedule by 2020. CDC and the World Health Organization (WHO) evaluated the WHO and United Nations Children's Fund (UNICEF) global vaccination coverage estimates to describe changes in global and regional coverage as of 2016. Global coverage estimates for the third dose of diphtheria and tetanus toxoids and pertussis-containing vaccine (DTP3), the third dose of polio vaccine, and the first dose of measles-containing vaccine (MCV1) have ranged from 84% to 86% since 2010. The dropout rate (the proportion of children who started but did not complete a vaccination series), an indicator of immunization program performance, was estimated to be 5% in 2016 for the 3-dose DTP series, with dropout highest in the African Region (11%) and lowest in the Western Pacific Region (0.4%...

Pan African Medical Journal, 2017

Introduction: in 2010, the Global Vaccine Action Plan called on all countries to reach and sustai... more Introduction: in 2010, the Global Vaccine Action Plan called on all countries to reach and sustain 90% national coverage and 80% coverage in all districts for the third dose of diphtheria-tetanus-pertussis vaccine (DTP3) by 2015 and for all vaccines in national immunization schedules by 2020. The aims of this study are to analyze recent trends in national vaccination coverage in the World Health Organization African Region andto assess how these trends differ by country income category. Methods: we compared national vaccination coverage estimates for DTP3 and the first dose of measles-containing vaccine (MCV) obtained from the World Health Organization (WHO)/United Nations Children's Fund (UNICEF) joint estimates of national immunization coverage for all African Region countries. Using United Nations (UN) population estimates of surviving infants and country income category for the corresponding year, we calculated population-weighted average vaccination coverage by country income category (i.e., low, lower middle, and upper middle-income) for the years 2000, 2005, 2010 and 2015. Results: DTP3 coverage in the African Region increased from 52% in 2000 to 76% in 2015,and MCV1 coverage increased from 53% to 74% during the same period, but with considerable differences among countries. Thirty-six African Region countries were low income in 2000 with an average DTP3 coverage of 50% while 26 were low income in 2015 with an average coverage of 80%. Five countries were lower middle-income in 2000 with an average DTP3 coverage of 84% while 12 were lower middle-income in 2015 with an average coverage of 69%. Five countries were upper middleincome in 2000 with an average DTP3 coverage of 73% and eight were upper middle-income in 2015 with an average coverage of 76%. Conclusion: disparities in vaccination coverage by country persist in the African Region, with countries that were lower middle-income having the lowest coverage on average in 2015. Monitoring and addressing these disparities is essential for meeting global immunization targets.

MMWR. Morbidity and Mortality Weekly Report, 2016

In 1974, the World Health Organization (WHO) established the Expanded Program on Immunization* to... more In 1974, the World Health Organization (WHO) established the Expanded Program on Immunization* to provide protection against six vaccine-preventable diseases through routine infant immunization (1). Based on 2015 WHO and United Nations Children's Fund (UNICEF) estimates, global coverage with the third dose of diphtheria-tetanus-pertussis vaccine (DTP3), the first dose of measles-containing vaccine (MCV1) and the third dose of polio vaccine (Pol3) has remained stable (84%-86%) since 2010. From 2014 to 2015, estimated global coverage with the second MCV dose (MCV2) increased from 39% to 43% by the end of the second year of life and from 58% to 61% when older age groups were included. Global coverage was higher in 2015 than 2010 for newer or underused vaccines, including rotavirus vaccine, pneumococcal conjugate vaccine (PCV), rubella vaccine, Haemophilus influenzae type b (Hib) vaccine, and 3 doses of hepatitis B (HepB3) vaccine. Coverage estimates varied widely by WHO Region, country, and district; in addition, for the vaccines evaluated (MCV, DTP3, Pol3, HepB3, Hib3), wide disparities were found in coverage by country income classification. Improvements in equity of access are necessary to reach and sustain higher coverage and increase protection from vaccine-preventable diseases for all persons. WHO and UNICEF derive national coverage estimates through an annual country-by-country review of all available data, including administrative † and survey-based § reviews (2,3). To analyze equity of vaccination coverage, countries were categorized by World Bank income classification (low, lower-middle, upper-middle, high) based on 2015 per capita gross national income (GNI) (4) and eligibility for financial support from Gavi, the Vaccine Alliance (Gavi), for new vaccine introduction at any time since 2005 ¶ (5). Eligibility for Gavi support is typically based on a country's GNI per capita;

MMWR. Morbidity and Mortality Weekly Report, 2015

In 2000, the United Nations General Assembly adopted the Millennium Development Goals (MDG), with... more In 2000, the United Nations General Assembly adopted the Millennium Development Goals (MDG), with MDG4 being a two-thirds reduction in child mortality by 2015, and with measles vaccination coverage being one of the three indicators of progress toward this goal.* In 2010, the World Health Assembly established three milestones for measles control by 2015: 1) increase routine coverage with the first dose of measles-containing vaccine (MCV1) for children aged 1 year to ≥90% nationally and ≥80% in every district; 2) reduce global annual measles incidence to fewer than five cases per million population; and 3) reduce global measles mortality by 95% from the 2000 estimate (1).† In 2012, the World Health Assembly endorsed the Global Vaccine Action Plan§ with the objective to eliminate measles in four World Health Organization (WHO) regions by 2015. WHO member states in all six WHO regions have adopted measles elimination goals. This report updates the 2000–2013 report (2) and describes progress toward global control and regional measles elimination during 2000–2014. During this period, annual reported measles incidence declined 73% worldwide, from 146 to 40 cases per million population, and annual estimated measles deaths declined 79%, from 546,800 to 114,900. However, progress toward the 2015 milestones and elimination goals has slowed markedly since 2010. To resume progress toward milestones and goals for measles elimination, a review of current strategies and challenges to improving program performance is needed, and countries and their partners need to raise the visibility of measles elimination, address barriers to measles vaccination, and make substantial and sustained additional investments in strengthening health systems.

World Journal of Vaccines, 2014

Background: In order to effectively plan the delivery of immunization services, manage stock and ... more Background: In order to effectively plan the delivery of immunization services, manage stock and supply levels and target interventions, national immunization programmes (NIP) must have an estimate of the target population they serve. To overcome challenges with target population estimation, some NIPs apply "rule-of-thumb" conversion factors to total population estimates. We compare these proportionate target population values with those from an external source. Methods: Using data reported by national immunization programmes in sub-Saharan Africa, we computed the proportionate target population as the number of births, surviving infants and children under 5 years of age, respectively, as a proportion of the total population size. We compared these values with those estimates computed from United Nations Population Division (UNPD) data. We then recomputed NIP target population sizes using the proportionate target population values from the UNPD applied to the total population size reported by NIP. Results: Data were available from 47 sub-Saharan Africa countries. Births as a proportion of the total population were greater within reports from NIP (median, 0.0400; IQR: 0.350-0.0437) compared to values from UNPD estimates (median, 0.0364; IQR: 0.0332-0.0406). Similar patterns were observed for surviving infants (median: NIP, 0.0360; UNPD, 0.0337) and children under 5 years of age (median: NIP, 0.1735; UNPD, 0.1594). The percent difference in proportionate target population ratios between reports from NIPs and the UNPD was >10% in 23 countries for births, in 18 countries for surviving infants, * Corresponding author. D. W. Brown et al. 148 in 15 countries for children under 5 years of age. After re-computing target populations using UNPD proportionate target population values applied to NIP reported total population, recomputed administrative coverage levels for the third dose of DTP containing vaccine were higher in 32 of the 47 countries compared to reported administrative coverage levels. Conclusion: Because childhood immunization-related target populations are among the more difficult ones to accurately estimate and project, immunization programmes in sub-Saharan Africa are encouraged to include a critical assessment of the target population values, in conjunction with their national statistics system, as part of the ongoing programme monitoring process.

World Journal of Vaccines, 2014

Background: Comparison of target populations for immunization used by national immunization progr... more Background: Comparison of target populations for immunization used by national immunization programmes with independent sources can be useful for identifying irregular patterns. Similarly, understanding differences in computed coverage levels that result from changes in target population estimates can be important. Methods: Using data reported annually by national immunization programmes to WHO and UNICEF, we compared the national number of births and surviving infants with estimates reported by the United Nations Population Division (UNPD). We also re-computed and compared coverage levels for the third dose of DTP containing vaccine (DTP 3) using the nationally reported number of children vaccinated with DTP 3 (the numerator) and the nationally reported number of children in the target population (the denominator) and compared this value with DTP 3 coverage computed using the nationally reported number of children vaccinated and the UNPD estimate of the national number of surviving infants as an independent denominator. Results: We observed differences in the number of births and surviving infants reported by national immunization programmes compared with those estimated by the UNPD. Year-to-year changes in the number of births and surviving infants reported by national immunization programmes often exceeded those estimated by the UNPD. The re-computed administrative coverage levels for DTP 3 using a nationally reported target population tended to be higher on average than those re-computed using the UNPD target population estimates. Conclusion: Target population estimates are a challenge for immunization programmes, and comparison to independent sources can be useful. There is increasing need to trace and better understand the processes and conditions affecting the enumeration and recording of the number of children in the target population for immunization services and the number of children vaccinated while recognizing that the challenge to do so is greater in some locations than others.

World Journal of Vaccines, 2014

There have been tremendous improvements in immunization coverage since the Expanded Programme on ... more There have been tremendous improvements in immunization coverage since the Expanded Programme on Immunization was launched. We highlight inherent challenges in measuring immunization coverage with precision as coverage levels increase due to the sensitivity of coverage to the accuracy of target population estimates. In fact, when comparing across groups at high levels of coverage, error in target population estimates can obscure differences in immunization coverage.

MMWR. Morbidity and mortality weekly report, Jan 7, 2014

In 2010, the World Health Assembly established three milestones toward global measles eradication... more In 2010, the World Health Assembly established three milestones toward global measles eradication to be reached by 2015: 1) increase routine coverage with the first dose of measles-containing vaccine (MCV1) for children aged 1 year to ≥90% nationally and ≥80% in every district, 2) reduce and maintain annual measles incidence at <5 cases per million, and 3) reduce measles mortality by 95% from the 2000 estimate. After the adoption by member states of the South-East Asia Region (SEAR) of the goal of measles elimination by 2020, elimination goals have been set by member states of all six World Health Organization (WHO) regions, and reaching measles elimination in four WHO regions by 2015 is an objective of the Global Vaccine Action Plan (GVAP). This report updates the previous report for 2000-2011 and describes progress toward global control and regional elimination of measles during 2000-2012. During this period, increases in routine MCV coverage, plus supplementary immunization ac...

MMWR. Morbidity and mortality weekly report, Jan 21, 2014

In 1974, the World Health Organization (WHO) established the Expanded Program on Immunization to ... more In 1974, the World Health Organization (WHO) established the Expanded Program on Immunization to ensure that all children have access to routinely recommended vaccines. Since then, global coverage with the four core vaccines (Bacille Calmette-Guérin vaccine [for protection against tuberculosis], diphtheria-tetanus-pertussis vaccine [DTP], polio vaccine, and measles vaccine) has increased from <5% to ≥84%, and additional vaccines have been added to the recommended schedule. Coverage with the third dose of DTP vaccine (DTP3) by age 12 months is a key indicator of immunization program performance. Estimated global DTP3 coverage has remained at 83%-84% since 2009, with estimated 2013 coverage at 84%. Global coverage estimates for the second routine dose of measles-containing vaccine (MCV2) are reported for the first time in 2013; global coverage was 35% by the end of the second year of life and 53% when including older age groups. Improvements in equity of access and use of immunizat...

PloS one, 2012

Production of official statistics frequently requires expert judgement to evaluate and reconcile ... more Production of official statistics frequently requires expert judgement to evaluate and reconcile data of unknown and varying quality from multiple and potentially conflicting sources. Moreover, exceptional events may be difficult to incorporate in modelled estimates. Computational logic provides a methodology and tools for incorporating analyst's judgement, integrating multiple data sources and modelling methods, ensuring transparency and replicability, and making documentation computationally accessible. Representations using computational logic can be implemented in a variety of computer-based languages for automated production. Computational logic complements standard mathematical and statistical techniques and extends the flexibility of mathematical and statistical modelling. A basic overview of computational logic is presented and its application to official statistics is illustrated with the WHO…

The Lancet, 2007

Background In 2002, the UN General Assembly Special Session on Children adopted a goal to reduce ... more Background In 2002, the UN General Assembly Special Session on Children adopted a goal to reduce deaths owing to measles by half by the end of 2005, compared with 1999 estimates. We describe efforts and progress made towards this goal. Methods We assessed trends in immunization against measles on the basis of national implementation of the WHO/UNICEF comprehensive strategy for measles mortality reduction, and the provision of a second opportunity for measles immunization. We used a natural history model to evaluate trends in mortality due to measles. Results Between 1999 and 2005, according to our model mortality owing to measles was reduced by 60%, from an estimated 873 000 deaths (uncertainty bounds 634 000-1 140 000) in 1999 to 345 000 deaths (247 000-458 000) in 2005. The largest percentage reduction in estimated measles mortality during this period was in the western Pacific region (81%), followed by Africa (75%) and the eastern Mediterranean region (62%). Africa achieved the largest total reduction, contributing 72% of the global reduction in measles mortality. Nearly 7•5 million deaths from measles were prevented through immunization between 1999 and 2005, with supplemental immunization activities and improved routine immunization accounting for 2•3 million of these prevented deaths. Interpretation The achievement of the 2005 global measles mortality reduction goal is evidence of what can be accomplished for child survival in countries with high childhood mortality when safe, costeffective, and affordable interventions are backed by country-level political commitment and an effective international partnership.