Abdu A. Adamu

57202024381

Publications - 2

Global, regional, and national trends in routine childhood vaccination coverage from 1980 to 2023 with forecasts to 2030: a systematic analysis for the Global Burden of Disease Study 2023

Simeon Okechukwu Ajakwe Mushood Ahmed Naveed Ahmed Rana Kamal Abu Farha Eman Abu-Gharbieh Aanuoluwapo Adeyimika Afolabi Giuseppina Affinito Kamoru Ademola Adedokun Nurudeen A. Adegoke Dolapo Emmanuel Ajala Armita Abedi Usha Adiga Mitra Abbasifard Mohammad Amin Aalipour Aqeel Ahmad Dariush Abtahi Ripon Kumar Adhikary Mohd Adnan Williams Agyemang-Duah Danish Ahmad Hana J. Abukhadijah Rotimi Felix Afolabi Saira Afzal Emad M. Abdallah Meqdad Saleh Ahmed Muktar Beshir Ahmed Syed Anees Ahmed Suneth Buddhika Agampodi Ayman Ahmed Khurshid Ahmad Tauseef Ahmad Sepehr Aghajanian Meriem Abdoun Salahdein Aburuz Lucas Guimarães Abreu Qorinah Estiningtyas Sakilah Adnani Olivia D. Nesbit Taylor Noyes Noga Shalev Latera Tesfaye Olana Catherine Bisignano Emily Haeuser Sam Byrne Jason Nguyen Catalina Raggi Susan A. McLaughlin Ashley A. Harris Amanda E. Smith Paulina A. Lindstedt Georgia Smith Samuel James Herold Rana Kamal Abu Farha Dmitry Abramov Sherief Abd-Elsalam Hedayat Abbastabar Faezeh Abbaspour Reda Abdel-Hameed Samar Abd ElHafeez Atef Abdelkader Adam Abdullahi Kulmira Abdykerimova Deldar Morad Abdulah Abdu A. Adamu Haroon Ahmed Rahim Abo Kasem Lisa C. Adams Toufik Abdul-Rahman Constanza Elizabeth Aguilera Arriagada Mahsa Ahadi Rabbiya Ahmad Shoaib Ahmad Asrat Agalu Abejew Juliana Bunmi Adetunji Bilyaminu Abubakar Ousman Adal Meshack Achore Nagah M. Abourashed Mohamed Abouzid David Adedia Oyelola A. Adegboye Habeeb Abiodun Afolabi Roberto Ariel Abeldaño Zuñiga Anirudh Balakrishna Acharya Juan Manuel Acuna Arman Abdous Auwal Abdullahi Hasan Aalruz Dhiraj Motilal Agarwal Syed Hani Abidi Abdullahi Tunde Aborode Olumide Abiodun Richard Gyan Aboagye Hassan Abolhassani Ulric Sena Abonie Wakgari Mosisa Abdisa Prince Owusu Adoma Leticia Akua Adzigbli Tajudeen Adesanmi Adebisi Oluwatobi E. Adegbile Olumide Thomas Adeleke Mache Tsadik Adhana

Publication Name: Lancet

Publication Date: 2025-07-19

Volume: 406

Issue: 10500

Page Range: 235-260

Description:

Background: Since its inception in 1974, the Essential Programme on Immunization (EPI) has achieved remarkable success, averting the deaths of an estimated 154 million children worldwide through routine childhood vaccination. However, more recent decades have seen persistent coverage inequities and stagnating progress, which have been further amplified by the COVID-19 pandemic. In 2019, WHO set ambitious goals for improving vaccine coverage globally through the Immunization Agenda 2030 (IA2030). Now halfway through the decade, understanding past and recent coverage trends can help inform and reorient strategies for approaching these aims in the next 5 years. Methods: Based on the Global Burden of Diseases, Injuries, and Risk Factors Study 2023, this study provides updated global, regional, and national estimates of routine childhood vaccine coverage from 1980 to 2023 for 204 countries and territories for 11 vaccine-dose combinations recommended by WHO for all children globally. Employing advanced modelling techniques, this analysis accounts for data biases and heterogeneity and integrates new methodologies to model vaccine scale-up and COVID-19 pandemic-related disruptions. To contextualise historic coverage trends and gains still needed to achieve the IA2030 coverage targets, we supplement these results with several secondary analyses: (1) we assess the effect of the COVID-19 pandemic on vaccine coverage; (2) we forecast coverage of select life-course vaccines up to 2030; and (3) we analyse progress needed to reduce the number of zero-dose children by half between 2023 and 2030. Findings: Overall, global coverage for the original EPI vaccines against diphtheria, tetanus, and pertussis (first dose [DTP1] and third dose [DTP3]), measles (MCV1), polio (Pol3), and tuberculosis (BCG) nearly doubled from 1980 to 2023. However, this long-term trend masks recent challenges. Coverage gains slowed between 2010 and 2019 in many countries and territories, including declines in 21 of 36 high-income countries and territories for at least one of these vaccine doses (excluding BCG, which has been removed from routine immunisation schedules in some countries and territories). The COVID-19 pandemic exacerbated these challenges, with global rates for these vaccines declining sharply since 2020, and still not returning to pre-COVID-19 pandemic levels as of 2023. Coverage for newer vaccines developed and introduced in more recent years, such as immunisations against pneumococcal disease (PCV3) and rotavirus (complete series; RotaC) and a second dose of the measles vaccine (MCV2), saw continued increases globally during the COVID-19 pandemic due to ongoing introductions and scale-ups, but at slower rates than expected in the absence of the pandemic. Forecasts to 2030 for DTP3, PCV3, and MCV2 suggest that only DTP3 would reach the IA2030 target of 90% global coverage, and only under an optimistic scenario. The number of zero-dose children, proxied as children younger than 1 year who do not receive DTP1, decreased by 74·9% (95% uncertainty interval 72·1–77·3) globally between 1980 and 2019, with most of those declines reached during the 1980s and the 2000s. After 2019, counts of zero-dose children rose to a COVID 19-era peak of 18·6 million (17·6–20·0) in 2021. Most zero-dose children remain concentrated in conflict-affected regions and those with various constraints on resources available to put towards vaccination services, particularly sub-Saharan Africa. As of 2023, more than 50% of the 15·7 million (14·6–17·0) global zero-dose children resided in just eight countries (Nigeria, India, Democratic Republic of the Congo, Ethiopia, Somalia, Sudan, Indonesia, and Brazil), emphasising persistent inequities. Interpretation: Our estimates of current vaccine coverage and forecasts to 2030 suggest that achieving IA2030 targets, such as halving zero-dose children compared with 2019 levels and reaching 90% global coverage for life-course vaccines DTP3, PCV3, and MCV2, will require accelerated progress. Substantial increases in coverage are necessary in many countries and territories, with those in sub-Saharan Africa and south Asia facing the greatest challenges. Recent declines will need to be reversed to restore previous coverage levels in Latin America and the Caribbean, especially for DTP1, DTP3, and Pol3. These findings underscore the crucial need for targeted, equitable immunisation strategies. Strengthening primary health-care systems, addressing vaccine misinformation and hesitancy, and adapting to local contexts are essential to advancing coverage. COVID-19 pandemic recovery efforts, such as WHO's Big Catch-Up, as well as efforts to bolster routine services must prioritise reaching marginalised populations and target subnational geographies to regain lost ground and achieve global immunisation goals. Funding: The Bill & Melinda Gates Foundation and Gavi, the Vaccine Alliance.

Open Access: Yes

DOI: 10.1016/S0140-6736(25)01037-2

Global burden of 292 causes of death in 204 countries and territories and 660 subnational locations, 1990–2023: a systematic analysis for the Global Burden of Disease Study 2023

Niveen M.E. Abu-Rmeileh Nermeen Abu-Elala Jeza Muhamad Abdul Aziz Shehab Uddin Al Abid Rana Kamal Abu Farha Cristiana Abbafati Faezeh Abbaspour Madineh Abbasi Barkhad Aden Abdeeq Nadin M.I. Abdel Razeq Mohammed Altigani Abdalla Abdallah H.A. Abd Al Magied Reda Abdel-Hameed Wael M. Abdel-Rahman Ahmed Abdelrahman Abdelgalil Bulcha Guye Adema Bashir Aden Michael Abdelmasseh Aminu Kende Abubakar Eman Abu-Gharbieh Isaac Ayodeji Adesina Aanuoluwapo Adeyimika Afolabi Giuseppina Affinito Thilini Chanchala Agampodi Kamoru Ademola Adedokun Nurudeen A. Adegoke Ashraf Nabiel Abdalla Habtamu Abebe Getahun Lisa C. Adams Clifford Afoakwah Armita Abedi Usha Adiga Hmwe Hmwe Kyu A. Bhoomadevi Mohammad Amin Aalipour Bedru J. Abafita Hazim S. Ababneh Ukachukwu O. Abaraogu Dariush Abtahi Ripon Kumar Adhikary Mohd Adnan Tanin Adl Parvar Alemwork Abie Hana J. Abukhadijah Rotimi Felix Afolabi Habtamu Abebe Getahun Tanin Adl Parvar Vlad Adrian Afrăsânie Saira Afzal Gizachew Beykaso Agafari Emad M. Abdallah Samar Abd ElHafeez Suneth Buddhika Agampodi Mohsen Naghavi Salahdein Aburuz Mahmoud Abdelnabi Lucas Guimarães Abreu Apurba Acharya Manfred Mario Kokou Accrombessi Jeza Muhamad Abdul Aziz Oluwafemi Atanda Adeagbo Qorinah Estiningtyas Sakilah Adnani Ahmed M. Afifi Hedayat Abbastabar Samar Abd ElHafeez Deldar Morad Abdulah Abdu A. Adamu Toufik Abdul-Rahman Asrat Agalu Abejew Dmitry Abramov Juliana Bunmi Adetunji Fuad Hamdi A. Abuadas Sawsan Abuhammad Ousman Adal Parisa Abedi Mostafa M. Abdrabou Aidin Abedi Olugbenga Olusola Abiodun Shady Abohashem Nagah M. Abourashed Mohamed Abouzid Roberto Ariel Abeldaño Zuñiga Anirudh Balakrishna Acharya Isaac Yeboah Addo Arman Abdous Auwal Abdullahi David Adzrago Hasan Aalruz Syed Hani Abidi Richard Gyan Aboagye Hassan Abolhassani Ulric Sena Abonie Habeeb Omoponle Adewuyi Prince Owusu Adoma Leticia Akua Adzigbli Isaac Akinkunmi Adedeji Ahmad Y. Abuhelwa Dina Abushanab Tajudeen Adesanmi Adebisi Oluwatobi E. Adegbile Olumide Thomas Adeleke Miracle Ayomikun Adesina Temitayo Esther Adeyeoluwa Mache Tsadik Adhana

Publication Name: Lancet

Publication Date: 2025-10-18

Volume: 406

Issue: 10513

Page Range: 1811-1872

Description:

Background Timely and comprehensive analyses of causes of death stratified by age, sex, and location are essential for shaping effective health policies aimed at reducing global mortality. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2023 provides cause-specific mortality estimates measured in counts, rates, and years of life lost (YLLs). GBD 2023 aimed to enhance our understanding of the relationship between age and cause of death by quantifying the probability of dying before age 70 years (70q0) and the mean age at death by cause and sex. This study enables comparisons of the impact of causes of death over time, offering a deeper understanding of how these causes affect global populations. Methods GBD 2023 produced estimates for 292 causes of death disaggregated by age-sex-location-year in 204 countries and territories and 660 subnational locations for each year from 1990 until 2023. We used a modelling tool developed for GBD, the Cause of Death Ensemble model (CODEm), to estimate cause-specific death rates for most causes. We computed YLLs as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. Probability of death was calculated as the chance of dying from a given cause in a specific age period, for a specific population. Mean age at death was calculated by first assigning the midpoint age of each age group for every death, followed by computing the mean of all midpoint ages across all deaths attributed to a given cause. We used GBD death estimates to calculate the observed mean age at death and to model the expected mean age across causes, sexes, years, and locations. The expected mean age reflects the expected mean age at death for individuals within a population, based on global mortality rates and the population's age structure. Comparatively, the observed mean age represents the actual mean age at death, influenced by all factors unique to a location-specific population, including its age structure. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 250-draw distribution for each metric. Findings are reported as counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2023 include a correction for the misclassification of deaths due to COVID-19, updates to the method used to estimate COVID-19, and updates to the CODEm modelling framework. This analysis used 55 761 data sources, including vital registration and verbal autopsy data as well as data from surveys, censuses, surveillance systems, and cancer registries, among others. For GBD 2023, there were 312 new country-years of vital registration cause-of-death data, 3 country-years of surveillance data, 51 country-years of verbal autopsy data, and 144 country-years of other data types that were added to those used in previous GBD rounds. Findings The initial years of the COVID-19 pandemic caused shifts in long-standing rankings of the leading causes of global deaths: it ranked as the number one age-standardised cause of death at Level 3 of the GBD cause classification hierarchy in 2021. By 2023, COVID-19 dropped to the 20th place among the leading global causes, returning the rankings of the leading two causes to those typical across the time series (ie, ischaemic heart disease and stroke). While ischaemic heart disease and stroke persist as leading causes of death, there has been progress in reducing their age-standardised mortality rates globally. Four other leading causes have also shown large declines in global age-standardised mortality rates across the study period: diarrhoeal diseases, tuberculosis, stomach cancer, and measles. Other causes of death showed disparate patterns between sexes, notably for deaths from conflict and terrorism in some locations. A large reduction in age-standardised rates of YLLs occurred for neonatal disorders. Despite this, neonatal disorders remained the leading cause of global YLLs over the period studied, except in 2021, when COVID-19 was temporarily the leading cause. Compared to 1990, there has been a considerable reduction in total YLLs in many vaccine-preventable diseases, most notably diphtheria, pertussis, tetanus, and measles. In addition, this study quantified the mean age at death for all-cause mortality and cause-specific mortality and found noticeable variation by sex and location. The global all-cause mean age at death increased from 46·8 years (95% UI 46·6–47·0) in 1990 to 63·4 years (63·1–63·7) in 2023. For males, mean age increased from 45·4 years (45·1–45·7) to 61·2 years (60·7–61·6), and for females it increased from 48·5 years (48·1–48·8) to 65·9 years (65·5–66·3), from 1990 to 2023. The highest all-cause mean age at death in 2023 was found in the high-income super-region, where the mean age for females reached 80·9 years (80·9–81·0) and for males 74·8 years (74·8–74·9). By comparison, the lowest all-cause mean age at death occurred in sub-Saharan Africa, where it was 38·0 years (37·5–38·4) for females and 35·6 years (35·2–35·9) for males in 2023. Lastly, our study found that all-cause 70q0 decreased across each GBD super-region and region from 2000 to 2023, although with large variability between them. For females, we found that 70q0 notably increased from drug use disorders and conflict and terrorism. Leading causes that increased 70q0 for males also included drug use disorders, as well as diabetes. In sub-Saharan Africa, there was an increase in 70q0 for many non-communicable diseases (NCDs). Additionally, the mean age at death from NCDs was lower than the expected mean age at death for this super-region. By comparison, there was an increase in 70q0 for drug use disorders in the high-income super-region, which also had an observed mean age at death lower than the expected value. Interpretation We examined global mortality patterns over the past three decades, highlighting—with enhanced estimation methods—the impacts of major events such as the COVID-19 pandemic, in addition to broader trends such as increasing NCDs in low-income regions that reflect ongoing shifts in the global epidemiological transition. This study also delves into premature mortality patterns, exploring the interplay between age and causes of death and deepening our understanding of where targeted resources could be applied to further reduce preventable sources of mortality. We provide essential insights into global and regional health disparities, identifying locations in need of targeted interventions to address both communicable and non-communicable diseases. There is an ever-present need for strengthened health-care systems that are resilient to future pandemics and the shifting burden of disease, particularly among ageing populations in regions with high mortality rates. Robust estimates of causes of death are increasingly essential to inform health priorities and guide efforts toward achieving global health equity. The need for global collaboration to reduce preventable mortality is more important than ever, as shifting burdens of disease are affecting all nations, albeit at different paces and scales. Funding Gates Foundation.

Open Access: Yes

DOI: 10.1016/S0140-6736(25)01917-8