The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health, officially established on April 7, 1948, when its Constitution came into force [1]. This date is commemorated annually as World Health Day. The WHO was created in response to the devastation of the Second World War, with the aim of coordinating global efforts to prevent disease, improve public health, and establish international health standards. Headquartered in Geneva, Switzerland, the organization currently comprises 194 member states and operates as the leading authority on global health governance [2]. Its foundational Constitution defines health as "a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity," a holistic concept that continues to shape its mission [2]. The WHO plays a central role in leading and coordinating international responses to public health emergencies, such as pandemics and outbreaks, through mechanisms like the International Health Regulations and declarations of a Public Health Emergency of International Concern. It develops evidence-based guidelines and norms, including the International Classification of Diseases, and supports countries in strengthening their health systems, promoting Universal Health Coverage, and combating both communicable diseases like tuberculosis and non-communicable diseases like diabetes. The organization's landmark achievements include the global eradication of smallpox in 1980 and significant progress toward the eradication of polio. The WHO's governing bodies, the World Health Assembly and the Executive Board, set policy and approve its budget, while the Director-General provides leadership. Despite its successes, the WHO faces ongoing challenges related to its funding model, which relies heavily on voluntary contributions, raising concerns about its autonomy and the influence of major donors like the United States and the Bill & Melinda Gates Foundation. The organization has undergone reforms, particularly after its response to the 2014 Ebola outbreak and the COVID-19 pandemic, leading to the creation of the WHO Health Emergencies Programme and ongoing negotiations for a new Pandemic Treaty to strengthen global preparedness and ensure equitable access to vaccines and treatments [4].
Founding and Historical Context
The World Health Organization (WHO) was officially founded on April 7, 1948, when its Constitution came into force [1]. This date is commemorated annually as World Health Day and marks the formal beginning of the organization as a specialized agency of the United Nations. The creation of the WHO emerged from a global recognition, particularly in the aftermath of the Second World War, of the need for a permanent, coordinated international body dedicated to public health [6]. The devastation of the war had exposed the catastrophic consequences of fragmented health systems, the unchecked spread of infectious diseases like cholera, plague, and yellow fever, and the vulnerability of populations to health crises, highlighting that health was no longer a purely national concern but a fundamental aspect of international peace and security [6].
Origins and the Path to Establishment
The formal process of establishing the WHO began during the 1945 United Nations Conference on International Organization in San Francisco, where delegates from countries including Brazil and China proposed the creation of a world health organization [6]. This proposal gained widespread support, reflecting a post-war consensus on the importance of health as a pillar of global stability and development. The pivotal moment came in 1946 with the International Health Conference held in New York, where 61 nations gathered to draft and adopt the Constitution of the WHO [9]. This foundational document was revolutionary for its time, defining health not merely as the absence of disease, but as "a state of complete physical, mental and social well-being" [10]. This holistic definition set a new, ambitious standard for public health and underscored the organization's comprehensive mandate.
Following the conference, an Interim Commission of the WHO was established to manage the transition period and prepare for the organization's launch. The Constitution officially entered into force on April 7, 1948, after being ratified by at least 26 member states, marking the official birth of the WHO and the beginning of its operations [11].
Differentiation from Predecessor Organizations
The WHO represented a significant evolution from its predecessors in international health. Earlier bodies, such as the Pan American Sanitary Bureau (founded in 1902, later the Pan American Health Organization) and the International Office of Public Hygiene (1907), were often regional or focused on specific diseases like quarantine measures [12]. They lacked the universal membership, permanent structure, and broad mandate of the WHO. The Health Section of the League of Nations, for instance, was hampered by limited funding and a lack of independent political power [13]. In contrast, the WHO was conceived from the outset as a global, universal, and specialized agency within the newly formed United Nations system. It was endowed with a formal governance structure, including the supreme decision-making body, the World Health Assembly, and a permanent secretariat led by a Director-General, giving it unprecedented authority to set international health standards and coordinate a global response to health threats [14].
The Influence of the Cold War
Although founded in a spirit of post-war cooperation, the WHO's early years were immediately shaped by the geopolitical tensions of the Cold War. The rivalry between the United States and the Soviet Union influenced debates on the organization's governance, funding, and priorities. The United States advocated for a model of public health based on science and technology, while the Soviet Union and other Eastern Bloc countries expressed concerns about Western dominance and the organization's independence [15]. These tensions were evident in discussions about the location of the WHO's headquarters, which was ultimately established in neutral Geneva, Switzerland, to accommodate all parties [15]. Despite these challenges, the WHO managed to maintain a space for technical cooperation, most notably in the successful global campaign to eradicate smallpox, where the United States and the Soviet Union collaborated on vaccine production and distribution, demonstrating that health could serve as a rare field of diplomacy even during intense geopolitical conflict [17]. This early history established the WHO as a central, albeit often contested, actor in global health governance.
Mission, Objectives, and Core Functions
The World Health Organization (WHO) operates with a clear and ambitious mission: to promote, protect, and improve the health of populations worldwide by coordinating international efforts, formulating health policies, and implementing actions to ensure the well-being of people in every country [2]. At its core, the organization's mission is to help all people achieve the highest possible level of health, a concept defined not merely as the absence of disease but as a state of complete physical, mental, and social well-being [19]. This holistic definition, enshrined in the WHO's Constitution, has been a foundational principle since its inception and continues to shape its global health agenda. The organization's vision, updated in 2025, is to advance health for all, everywhere, through sustained, equitable, and concerted actions that foster international cooperation and innovation in public health [20].
Core Objectives and Strategic Goals
The WHO's overarching objective is to achieve the highest attainable standard of health for all people, a mandate that drives its diverse portfolio of work. This mission is operationalized through several central objectives. A primary goal is the promotion of Universal Health Coverage (UHC), which ensures that all individuals can access essential health services of high quality without suffering financial hardship. This objective is aligned with the United Nations' Sustainable Development Goals (SDGs), particularly SDG 3, which aims to ensure healthy lives and promote well-being for all at all ages [21]. To achieve this, the WHO provides technical support to member states to strengthen their health systems, improve access to medical services, and develop effective health policies.
Another key objective is the reduction of global health inequalities. The organization works to address the profound disparities in health outcomes that are rooted in social, economic, and environmental determinants, such as poverty, education, and discrimination [22]. It does this by advocating for policies that promote equity, gender equality, and human rights in health care settings. The WHO also places a strong emphasis on preventing disease and promoting health. This includes leading global efforts to combat both communicable diseases like tuberculosis and non-communicable diseases (NCDs) such as diabetes, cardiovascular diseases, and cancer, which now represent the leading cause of death globally [23]. Its strategies for NCDs focus on tackling shared risk factors like tobacco use, unhealthy diets, physical inactivity, and harmful use of alcohol through cost-effective interventions known as "best buys" [24].
Core Functions and Operational Mandate
To fulfill its mission and objectives, the WHO performs a range of core functions that establish it as the leading authority in global health governance. Its first and most critical function is providing leadership and coordination on global health matters. The WHO acts as the rector and coordinator of the international public health response, particularly during emergencies such as pandemics, epidemics, natural disasters, and conflicts. It leads the global response by mobilizing resources, coordinating actors, and providing strategic direction [25].
A second fundamental function is the establishment of international health norms and standards. The WHO develops and promotes evidence-based guidelines and technical standards that serve as a global reference. This includes the International Classification of Diseases (ICD), which is used to track health trends and statistics worldwide [26]. It also sets standards for the safety and efficacy of medicines, vaccines, and medical devices, and issues guidelines on clinical practices and public health interventions.
The third core function is epidemiological surveillance and monitoring of global health. The WHO collects, analyzes, and disseminates vast amounts of data on global health trends, enabling the early detection of health threats and the assessment of progress toward health goals. This function is supported by sophisticated systems like the Early Warning and Response System (EWARS) and the Epidemic Intelligence from Open Sources (EIOS) platform, which scan global data to identify potential outbreaks [27].
The fourth function is providing technical assistance to countries. The WHO offers direct support to its 194 member states to build resilient and equitable health systems. This includes helping countries strengthen their capacity for disease prevention, diagnosis, and treatment, as well as training health workers and improving health infrastructure [28]. This support is often delivered through country-specific cooperation strategies developed in partnership with national governments.
The fifth function is governance in global health. Through its supreme decision-making body, the World Health Assembly (WHA), and the Executive Board, the WHO sets global health policy, adopts resolutions, and defines international health priorities with the full participation of all member states [29]. This democratic process ensures that the organization's agenda reflects the collective will of the international community.
Finally, the WHO plays a vital role in promoting research and innovation. It fosters scientific research in public health, supports the development of new medical technologies and treatments, and facilitates the global dissemination of scientific knowledge to improve health outcomes [25]. This includes initiatives to accelerate research during emergencies and to ensure that new health technologies are accessible to all, not just the wealthy.
Governance Structure and Decision-Making
The governance structure of the World Health Organization (WHO) is designed to ensure global representation, technical leadership, and accountability in international public health. As a specialized agency of the United Nations, the WHO operates through a hierarchical yet collaborative system composed of three principal organs: the World Health Assembly (WHA), the Executive Board, and the Director-General. These bodies work in concert to set policy, approve budgets, oversee implementation, and respond to global health emergencies, all within a framework defined by the WHO Constitution and the International Health Regulations.
World Health Assembly: Supreme Governing Body
The World Health Assembly (WHA) is the highest decision-making authority of the WHO, functioning as a global parliament of health. Composed of delegations from all 194 member states, the WHA convenes annually in Geneva, Switzerland, typically in May [31]. Its core responsibilities include:
- Setting the organization’s broad policies and strategic direction
- Approving the biennial program budget and financial plans
- Electing the Director-General for a five-year term, renewable once
- Reviewing and adopting resolutions on pressing global health issues
- Overseeing the performance and accountability of the Executive Board and Secretariat
Recent sessions, such as the 78th WHA in 2025, have achieved landmark outcomes, including the adoption of a historic Pandemic Treaty aimed at strengthening global preparedness and ensuring equitable access to vaccines and treatments [4]. The Assembly also plays a critical role in reforming the WHO’s governance, such as approving a 2022 decision to enhance sustainable financing by gradually increasing member states’ assessed contributions [33].
Executive Board: Policy Implementation and Oversight
The Executive Board, also known as the Executive Committee, acts as an intermediary body between the WHA and the Secretariat. It consists of 34 technically qualified members in the field of health, elected by the WHA for three-year terms to ensure equitable geographical representation [34]. The Board meets at least twice a year and is responsible for:
- Implementing the decisions and policies adopted by the WHA
- Preparing the agenda for the annual Assembly
- Supervising the execution of the WHO’s program of work
- Providing guidance on technical and administrative matters
In 2024, the Executive Board addressed critical issues such as antimicrobial resistance, climate change and health, and universal health coverage, reflecting its role in shaping the global health agenda between Assembly sessions [35]. It also plays a key role in the selection of the Director-General, reviewing candidates and making recommendations to the WHA.
Director-General: Executive Leadership and Technical Authority
The Director-General serves as the chief executive officer and principal technical leader of the WHO. Elected by the WHA, the Director-General is responsible for:
- Directing and managing the day-to-day operations of the organization
- Formulating and executing global health policies and strategies
- Representing the WHO before governments, international bodies, and the public
- Supervising the WHO Secretariat and regional offices
Dr. Tedros Adhanom Ghebreyesus, re-elected for a second term in 2022, exemplifies the role’s dual mandate of technical expertise and diplomatic leadership [36]. The Director-General also chairs the Executive Board and presents key reports on the state of global health. In emergency contexts, the Director-General has the authority to convene the Emergency Committee under the International Health Regulations (IHR) to determine whether an event constitutes a Public Health Emergency of International Concern (PHEIC) and to issue temporary recommendations [37]. For instance, in 2024, the Director-General declared the mpox outbreak a PHEIC, mobilizing a coordinated global response [38].
Emergency Committees and Crisis Decision-Making
Under the IHR (2005), the WHO has established Emergency Committees composed of independent experts who advise the Director-General on potential PHEICs. These committees have been activated for major crises, including the 2014 Ebola outbreak, the 2009 H1N1 influenza pandemic, and the 2020–2024 COVID-19 pandemic [39]. Their recommendations guide international travel and trade measures, surveillance, and response strategies.
In 2024, the WHO activated the Global Health Emergency Corps for the first time during the mpox outbreak, demonstrating a new operational capability for rapid deployment of personnel and resources [40]. This reflects structural reforms initiated after the 2014 Ebola crisis, including the creation of the WHO Health Emergencies Programme to ensure a faster, more predictable response [41].
Challenges in Governance: Sovereignty, Legitimacy, and Financing
Despite its institutional framework, the WHO faces persistent challenges in governance. A central tension lies between national sovereignty and the need for coordinated global action. Some member states, including the United States and Slovakia, have expressed concerns that WHO instruments like the IHR and the proposed Pandemic Treaty could infringe on national autonomy [42]. The WHO maintains that its recommendations are not binding and respect state sovereignty, though implementation depends on state cooperation.
Another major challenge is financial sustainability. The WHO relies heavily on voluntary contributions, which accounted for over 80% of its budget in 2024–2025 [43]. This dependence on major donors like the United States and the Bill & Melinda Gates Foundation raises concerns about the influence of donor priorities on the organization’s agenda and impartiality [44]. In January 2026, the United States notified its intention to withdraw from the WHO, a move that threatened the organization’s financial stability and global credibility [45].
To address these challenges, the WHA has approved reforms to increase assessed contributions and launched investment rounds to diversify funding [46]. However, the effectiveness of the WHO’s governance ultimately depends on its ability to balance technical authority with political legitimacy, ensure equitable participation, and maintain financial independence in an increasingly complex global health landscape.
Role in Global Health Emergencies and Pandemics
The World Health Organization (WHO) plays a central and multifaceted role in leading and coordinating the global response to health emergencies and pandemics. Its mandate includes the prevention, detection, response, and recovery from international health threats, ranging from infectious disease outbreaks to natural disasters and humanitarian crises. The organization acts as the principal coordinator for international public health action, leveraging a network of technical expertise, normative guidance, and emergency response mechanisms to protect populations worldwide [47].
Surveillance, Early Warning, and Detection Systems
A cornerstone of the WHO's emergency preparedness is its robust global surveillance and early warning infrastructure. The organization employs advanced systems to detect and monitor emerging health threats in real time. The Epidemic Intelligence from Open Sources (EIOS) platform analyzes data from media, official reports, and social networks to identify potential outbreaks, a system that has proven effective in the Americas [48]. Complementing this is the Early Warning and Response System (EWARS), which enables rapid detection of outbreaks even in areas with limited internet access [49].
In 2023, the WHO launched the International Pathogen Surveillance Network (IPSN), a global initiative to enhance genomic sequencing and data sharing, allowing for the early identification and containment of infectious disease threats [50]. The organization has also integrated artificial intelligence into its public health intelligence system to improve prediction and response capabilities, a move that significantly boosts global health security [51].
Coordination of Emergency Response and the Incident Management System
When a health emergency is detected, the WHO activates its Health Emergencies Programme, established in 2016 to ensure a rapid, predictable, and comprehensive response [52]. This program is built around the Incident Management System (IMST), a structured framework that enables coordinated action across multiple sectors and countries [53]. The IMST is supported by the Emergency Operations Centre (COE), which serves as the central hub for managing the organization's crisis response.
A landmark achievement in operational response was the first-ever activation of the Global Health Emergency Corps in October 2024, in response to the mpox outbreak. This specialized team was deployed to provide technical and logistical support, demonstrating the implementation of new rapid-response protocols [40]. The WHO also mobilizes critical financial and humanitarian resources through emergency appeals; for example, in 2026, it launched a global call to raise one billion dollars to sustain healthcare in complex humanitarian crises, including conflicts and climate-related disasters [55].
Declarations of Public Health Emergencies and the International Health Regulations
One of the WHO's most significant powers is its ability to declare a Public Health Emergency of International Concern (PHEIC) under the International Health Regulations (IHR) of 2005. This declaration signals a global health threat that requires a coordinated international response. The WHO Director-General makes this determination based on advice from an independent IHR Emergency Committee of experts [56].
Recent examples include the declaration of a PHEIC for the mpox outbreak in 2024 [38]. The IHR, a legally binding instrument for all 196 States Parties, obligates countries to report certain health events and to develop core capacities for surveillance and response. In 2024, the World Health Assembly approved a set of far-reaching amendments to the IHR, which entered into force in September 2025, aiming to strengthen global preparedness, improve transparency, and enhance the framework for international cooperation [39].
Development of Technical Guidance and Equitable Access to Medical Tools
During health emergencies, the WHO develops and disseminates evidence-based technical guidance to standardize care and response. This includes clinical protocols, such as those for prehospital care, and recommendations on infection prevention and control [59]. The organization also plays a crucial role in ensuring equitable access to medical countermeasures. It approved the first diagnostic test for mpox for emergency use in 2024, significantly boosting global access [60].
To address vaccine inequity, the WHO co-led the COVAX initiative during the COVID-19 pandemic, a global effort to accelerate the development and equitable distribution of COVID-19 vaccines [61]. The organization has also established an Access and Allocation Mechanism for mpox vaccines, treatments, and tests, ensuring their fair distribution based on technical criteria like disease burden and vulnerability [62]. The WHO's Essential Medicines List is updated regularly to include key treatments for emerging diseases, guiding national procurement and policy [63].
Evolution of Response and Lessons from Past Crises
The WHO's role in emergencies has evolved significantly in response to past crises. The 2014–2016 Ebola outbreak in West Africa exposed critical weaknesses in the organization's response speed and coordination, leading to widespread criticism [64]. In response, the WHO underwent major reforms, including the creation of the Health Emergencies Programme and a new contingency fund [41].
The COVID-19 pandemic further highlighted the need for a more robust and equitable global health architecture. This led to the negotiation and adoption of a historic Pandemic Agreement by the World Health Assembly in May 2025. This treaty aims to strengthen international cooperation, ensure equitable access to vaccines and treatments, and improve global preparedness for future pandemics [4]. This agreement, alongside the amended IHR, represents a significant step toward a more resilient and just global health security framework.
Development of Health Norms and Technical Guidance
The World Health Organization (WHO) plays a foundational role in the development of global health norms and technical guidance, serving as the leading authority in establishing standards that shape public health policy, clinical practice, and international cooperation. Through a rigorous, evidence-based process, the WHO formulates recommendations that are designed to be scientifically sound, technically feasible, and adaptable to diverse national contexts. These norms are critical for ensuring consistency, safety, and equity in health interventions worldwide, from disease classification to clinical care and pharmaceutical regulation.
Development and Standardization of Health Guidelines
The WHO develops its technical guidelines and norms through a structured, transparent, and participatory process grounded in scientific evidence. This process begins with the identification of public health needs, often arising from emerging diseases, scientific advancements, or requests from member states. The organization employs systematic reviews of evidence and utilizes methodologies such as the GRADE (Grading of Recommendations Assessment, Development and Evaluation) framework to assess the quality of evidence and formulate clear, actionable recommendations [67].
The development process involves multidisciplinary technical groups, advisory committees, and broad consultation with experts and stakeholders from around the world. This inclusive approach ensures that recommendations consider not only clinical efficacy but also ethical, operational, and cultural factors. Before final publication, draft guidelines undergo external peer review and public consultation with member states and other key actors to ensure clarity, relevance, and acceptability. The final recommendations are formally approved by WHO technical or governing bodies, such as the Guidelines Review Committee, and disseminated globally [68].
Recent examples of this process include the 2024 update of the WHO’s guidelines on laboratory biosecurity, which strengthen protocols for handling dangerous pathogens, and the 2026 influenza vaccine recommendations for the Southern Hemisphere, which incorporate global viral surveillance data and projections of potential pandemic strains [69][70].
Adaptation to Diverse Socioeconomic and Health System Contexts
Recognizing that health systems vary widely in resources and capacity, the WHO ensures that its guidelines are adaptable to different socioeconomic and health system contexts. The organization promotes flexible implementation strategies that account for disparities in infrastructure, workforce, and financing. For instance, the WHO issues context-specific recommendations for low- and middle-income countries, such as models for decentralized hearing care that utilize non-specialized health workers to improve access in resource-limited settings [71].
To support national adaptation, the WHO provides tools like the "Evidence for Impact" repository, launched in 2023, which facilitates evidence-based decision-making and the translation of global guidelines into national policies [72]. The organization also promotes task shifting—the delegation of clinical responsibilities to non-specialist health workers—as a strategy to expand access, particularly in areas with shortages of specialized personnel, such as in mental health care through the mhGAP Intervention Guide [73].
Key Technical Norms and Global Standards
Among the WHO’s most influential contributions is the International Classification of Diseases (ICD), a standardized system for diagnosing and reporting health conditions that enables global health monitoring and data comparability. The ICD is essential for epidemiological research, health policy planning, and resource allocation [26]. Another cornerstone is the Model List of Essential Medicines, which identifies the most effective, safe, and cost-effective medicines needed in a health system. Updated regularly, the list guides national procurement and reimbursement policies, with the 2025 revision including 35 new treatments for cancer and diabetes [63].
The WHO also sets standards for pharmaceutical quality and safety, including guidelines for good manufacturing practices and prequalification of vaccines and drugs, ensuring that health products meet international benchmarks. These standards are critical for programs like COVAX, which relies on WHO prequalification to distribute safe and effective vaccines equitably during global health emergencies [61].
Ethical and Cultural Considerations in Standard-Setting
The harmonization of global health standards presents significant ethical and practical challenges, particularly in balancing universal norms with cultural diversity and human rights. The WHO faces criticism for potentially imposing a Western biomedical model that may not align with local beliefs, traditional healing practices, or community values [77]. For example, in maternal and child health, the lack of culturally safe care—such as respect for traditional birth practices—can lead to distrust and reduced utilization of health services among indigenous and Afro-descendant populations [78].
To address these concerns, the WHO promotes intercultural dialogue in health and supports the integration of traditional medicine into national health systems through its Global Strategy on Traditional Medicine 2025–2034 [79]. The organization also emphasizes the need for health systems to be free from discrimination based on ethnicity, gender, disability, or migration status, advocating for human rights-based approaches in mental health and emergency care [80].
Legal and Normative Frameworks
The WHO’s authority in health norm-setting is grounded in its Constitution and reinforced by international legal instruments such as the International Health Regulations (IHR) 2005, a legally binding treaty that obligates member states to report public health events of international concern and to develop core surveillance and response capacities [37]. The IHR has been amended in 2025 to strengthen equity in access to vaccines and treatments and to improve transparency in outbreak reporting [82].
Complementing the IHR, the Pandemic Agreement, adopted in 2025, establishes a new global framework for equitable access to medical technologies and data sharing during pandemics, reflecting lessons learned from the COVID-19 pandemic and the Ebola virus epidemic in West Africa [4]. This treaty aims to balance global health security with respect for national sovereignty, ensuring that international norms support, rather than undermine, national health policies.
Achievements in Disease Eradication and Control
The World Health Organization (WHO) has achieved landmark successes in the global effort to eradicate and control infectious diseases, demonstrating the power of coordinated international action. Its most celebrated triumph remains the eradication of smallpox, a feat that stands as a defining moment in the history of public health. Beyond this singular achievement, the WHO has led sustained campaigns to eliminate other devastating diseases, such as polio and measles, and has supported numerous countries in eliminating diseases within their own borders. These efforts have been made possible through strategic vaccination programs, robust surveillance systems, and the establishment of global partnerships.
Eradication of Smallpox: A Historic Triumph
The eradication of smallpox is the WHO's most significant achievement in disease control. Officially declared in 1980, this victory marked the first and only time a human infectious disease has been completely eradicated from the planet [17]. The global campaign, which intensified with the launch of the formal Campaña Mundial de Erradicación de la Viruela in 1967, involved the vaccination of over 500 million people and the collaboration of thousands of health workers across more than 40 countries [85]. A key innovation was the adoption of the ring vaccination strategy, where health teams would identify active cases and vaccinate all close contacts, effectively containing the virus's spread without the need for mass vaccination of entire populations [86]. This success was a testament to international cooperation, even during the geopolitical tensions of the Cold War, as the United States and the Soviet Union collaborated on vaccine production and distribution [17]. The eradication of smallpox has prevented an estimated 200 million deaths and serves as an enduring model and source of inspiration for all future disease eradication efforts.
The Global Fight to Eradicate Polio
Building on the success of the smallpox campaign, the WHO has led a decades-long global initiative to eradicate polio. This effort has yielded substantial progress, with two of the three wild poliovirus strains declared eradicated: type 2 in 2015 and type 3 in 2019 [88]. The WHO's Estrategia de Erradicación de la Poliomielitis 2022–2026 continues to guide intensive vaccination campaigns in the few remaining endemic areas. The organization's ability to deliver critical public health services even in conflict zones was demonstrated in 2024 when it successfully conducted a polio vaccination campaign in Gaza, reaching more than 187,000 children [89]. Despite these gains, the persistence of the virus in some regions highlights the ongoing challenges of maintaining high vaccination coverage, ensuring surveillance in fragile states, and overcoming vaccine hesitancy. The WHO's work on polio has also pioneered the development of new tools and strategies, such as the use of novel oral polio vaccines (nOPV), to address the final hurdles to eradication.
Elimination of Diseases in Specific Countries
The WHO has played a crucial role in recognizing and supporting national efforts to eliminate diseases. Its certification of a country as having eliminated a disease is a significant public health milestone. In 2026, the WHO recognized Chile as the second country in the world to have eradicated leprosy, following over 30 years without any reported indigenous cases [90]. This achievement was the result of sustained national programs supported by WHO technical guidance. Similarly, the WHO, through its regional office the Pan American Health Organization (PAHO), has recognized countries for eliminating other diseases. For instance, Ecuador was acknowledged for maintaining a measles-free status, a success attributed to its robust mass vaccination campaigns and effective epidemiological surveillance systems [91]. These country-specific successes demonstrate the effectiveness of the WHO's model of providing technical assistance and normative guidance to strengthen national health systems.
Large-Scale Vaccination Campaigns and Global Impact
Beyond eradication and elimination, the WHO's Programa Ampliado de Inmunización (PAI) has been instrumental in controlling a wide range of diseases and saving millions of lives. This program, which promotes routine immunization against diseases like polio, measles, and rubella, is a cornerstone of the organization's disease control strategy. In 2023, a regional campaign in Latin America successfully vaccinated 3.4 million children against these diseases in just 14 weeks [92]. The impact of measles vaccination alone has been profound, with WHO data indicating that these vaccines have saved approximately 59 million lives over a 25-year period [93]. The PAI has evolved into the Agenda de Inmunización 2030, a global strategy aimed at leaving no one behind and extending the benefits of vaccination to underserved and vulnerable populations worldwide [94]. These massive vaccination drives are a direct legacy of the smallpox campaign and represent one of the most cost-effective public health interventions in history.
Strategies for Health System Strengthening and Universal Coverage
The World Health Organization (WHO) has long championed the strengthening of health systems and the advancement of Universal Health Coverage (UHC) as central pillars of its mission to achieve the highest attainable standard of health for all people. This strategic focus recognizes that robust, equitable, and resilient health systems are fundamental to preventing disease, responding to emergencies, and ensuring that no one is left behind due to financial hardship. The WHO's approach is multifaceted, encompassing normative guidance, technical support, and the promotion of global health equity.
The Foundational Role of Primary Health Care
A cornerstone of the WHO's strategy for health system strengthening is the revitalization and expansion of Primary Health Care (PHC). This approach was first enshrined in the landmark 1978 Declaration of Alma-Ata, which declared that health is a fundamental human right and established PHC as the key to achieving "Health for All" [95]. The declaration emphasized community participation, the integration of health with other sectors, and the importance of addressing the social, economic, and environmental determinants of health.
The principles of Alma-Ata remain highly relevant. In 2018, on the 40th anniversary of the declaration, the WHO and the Pan American Health Organization (PAHO) co-hosted the Astana Global Conference on Primary Health Care, which reaffirmed the commitment to PHC as the most efficient, effective, and equitable approach to achieving UHC and the Sustainable Development Goals [96]. This modernized framework calls for health systems to be reoriented around the needs and preferences of individuals and families, promoting prevention, health promotion, and comprehensive care throughout the life course.
Driving Progress Towards Universal Health Coverage
The WHO is a leading global advocate for UHC, working in close partnership with institutions like the World Bank to monitor progress and support countries in their journey toward equitable health systems. A joint report from 2025 found that while most countries have made progress toward UHC, significant challenges remain, particularly in low-income nations where per capita health spending is critically low at only USD 17, far below the estimated USD 60 needed for essential services [97][98]. The WHO's strategy involves supporting countries in increasing pre-paid, pooled funding for health, which protects people from catastrophic out-of-pocket expenses.
To provide targeted support, the WHO develops and implements Country Cooperation Strategies (CCS), which are collaborative frameworks designed in partnership with national governments. These strategies are built on a participatory process, aligning the WHO's technical and strategic support with a country's own health priorities and development plans. They address a wide range of areas, including health system reform, disease control, and capacity building. Recent examples include technical cooperation with Colombia and Bolivia to support their national health reforms, with formal cooperation strategies developed for the 2023-2027 period [99][100].
Promoting Equity and Addressing Structural Inequalities
A critical component of the WHO's strategy is addressing the deep-seated inequalities that hinder access to care. The organization recognizes that disparities in health are not only unjust but also preventable. To this end, it has developed tools like the Health Inequality Data Repository (HIDR), updated in 2026, which contains over 13 million data points on health inequities across different population groups [101]. This data is used to inform policies that aim to close the gap.
The WHO also promotes intersectoral action through initiatives like the Intersectoral Working Group for Health Equity in the Americas, which fosters social participation and collaboration across different government sectors to tackle the root causes of health inequity [102]. It emphasizes the need for a culturally sensitive and holistic approach to health, ensuring that services are accessible and respectful of diverse cultural, ethnic, and traditional medicine practices [77].
Leveraging Technology and Innovation
In the modern era, the WHO is also a key player in promoting the digital transformation of health systems. It supports the development and implementation of digital health solutions to improve service delivery and management. A prime example is the Todo en Uno platform, developed by PAHO, which integrates health data and information systems to enhance the management of services, particularly in Latin America and the Caribbean [104]. These digital tools are vital for reducing inefficiencies, improving decision-making, and building more resilient health systems, especially in the aftermath of disruptions like the COVID-19 pandemic [105].
Strengthening Immunization and Preventive Programs
The WHO's efforts to strengthen health systems are also evident in its leadership of global immunization programs. Through the Expanded Programme on Immunization (EPI), launched in 1974, the WHO has been instrumental in saving at least 154 million lives over the past 50 years [106]. The Immunization Agenda 2030 now aims to extend this protection to underserved populations, promoting vaccine equity and sustaining coverage even in the face of crises [94]. By preventing disease, these programs reduce the burden on health systems and are a cost-effective investment in long-term health and economic stability.
Challenges in Financing, Sovereignty, and Equity
The Organización Mundial de la Salud (WHO) faces persistent and interconnected challenges in the realms of financing, national sovereignty, and global health equity. These challenges shape its ability to fulfill its mandate of achieving the highest possible level of health for all people, often placing it at the center of geopolitical tensions and debates over the balance between international coordination and national autonomy.
Financial Vulnerability and the Crisis of Sustainable Funding
A fundamental challenge for the WHO is its financial structure, which is heavily reliant on voluntary contributions. While the organization receives mandatory contributions from its 194 member states, these represent less than 20% of its total budget. The vast majority of its funding comes from voluntary contributions, which are often earmarked for specific programs by donors, such as the United States or the Bill & Melinda Gates Foundation [43]. This model creates significant vulnerabilities, as it can condition the WHO's agenda and limit its ability to respond flexibly to emerging global health threats. The dependence on a small number of major donors raises concerns about the organization's autonomy and impartiality in global health governance [109].
This financial model has led to a crisis in sustainable funding. In 2025, a significant reduction in international health aid, estimated at up to 40%, put essential programs in low- and middle-income countries at risk [110]. In response, the World Health Assembly made a historic decision in 2022 to move towards more sustainable financing, proposing a gradual increase in assessed contributions from member states [33]. In 2024, the WHO launched its first investment round to finance its "Health for All" mandate, securing one billion dollars in funding commitments [46]. However, the withdrawal of the United States from the WHO in 2026, one of its largest contributors, created a major financial and operational crisis, highlighting the fragility of its funding base and its impact on global health security [113].
The Tension Between Global Health Governance and National Sovereignty
One of the most complex and enduring challenges for the WHO is navigating the delicate balance between its role as a global health coordinator and the principle of national sovereignty. The organization's authority is derived from international agreements like the International Health Regulations (IHR), which obligate member states to report public health events of international concern [37]. However, the IHR does not grant the WHO the power to impose measures or override a country's decisions, leaving the implementation of recommendations to the discretion of sovereign states.
This tension has been a source of significant debate and criticism. During the COVID-19 pandemic, the WHO was accused by some of being too cautious in its early warnings, while others criticized it for potentially overstepping its mandate. The negotiations for a new Pandemic Treaty have further intensified this debate. Critics, including some member states, have expressed concerns that such an agreement could undermine national sovereignty by allowing the WHO to impose restrictions or policies on domestic health matters [115]. The United States, for example, objected to proposed amendments to the IHR in 2024, arguing they could grant the WHO powers to impose restrictive measures without clear criteria [116]. The WHO has consistently maintained that its instruments, including the proposed pandemic accord, are designed to strengthen cooperation while fully respecting national sovereignty [117].
Persistent Inequities in Access to Health Technologies and Medicines
Despite its mission of health for all, the WHO confronts profound and persistent inequities in access to essential health technologies, medicines, and vaccines. The most glaring example of this was during the COVID-19 pandemic, where the Director-General, Tedros Adhanom Ghebreyesus, described the situation as a "vaccine apartheid," with low-income countries facing severe delays in accessing life-saving vaccines [118]. The COVAX initiative, co-led by the WHO, was created to ensure equitable distribution but struggled to overcome the barriers of supply and pricing set by wealthier nations and pharmaceutical companies.
These inequities extend beyond pandemics. Middle-income countries, which represent over 70% of the world's population, often fall into a "financing gap" where they are not eligible for the same level of donor support as low-income countries, yet they cannot afford the high prices of new vaccines and treatments [119]. The WHO has responded by promoting initiatives like the Access to COVID-19 Tools Accelerator (ACT-A) and the Technology Access Pool (HTAP), which aim to facilitate the sharing of intellectual property and knowledge to enable local production of medicines and vaccines [120]. The organization also maintains the List of Essential Medicines, which guides countries in prioritizing the most effective and safe treatments [63]. However, the fundamental power dynamics of the global pharmaceutical industry and intellectual property regimes remain a significant barrier to achieving true health equity.
Structural Inequities and the Legacy of Colonialism in Global Health
The challenges of equity are not merely logistical but are rooted in deep structural and historical injustices. Critics from the fields of medical anthropology and global health equity argue that the current system of global health governance, in which the WHO plays a central role, reproduces neocolonial dynamics [122]. The concentration of power, funding, and knowledge production in institutions of the Global North often leads to top-down interventions that fail to account for local contexts, cultures, and epistemologies. This "feudalization" of global health marginalizes the voices and expertise of communities in the Global South, undermining the effectiveness and legitimacy of health programs [123].
The WHO has recognized the importance of addressing these structural determinants of health, such as poverty, discrimination, and unequal power relations. It has promoted strategies for culturally safe care, particularly in maternal and child health and mental health, and has advocated for the integration of traditional medicine into national health systems [124]. However, transforming these policies into practice requires a more radical "decolonization" of global health, which involves redistributing power, ensuring equitable participation in decision-making, and recognizing the sovereignty of communities over their own health [125]. The organization's ability to overcome its own historical and structural biases will be critical to building truly inclusive and just health systems worldwide.