World Health Organization's List Research Articles

Transmitted Drug Resistance Among Antiretroviral-Naive Patients with Established HIV Type 1 Infection in Santo Domingo, Dominican Republic and Review of the Latin American and Caribbean Literature

Emergence of HIV resistance is a concerning consequence of global scale-up of antiretroviral therapy (ART). To date, there is no published information about HIV resistance from the Dominican Republic. The study's aim was to determine the prevalence of transmitted drug resistance (TDR) to reverse transcriptase and protease inhibitors in a sample of chronically HIV-1-infected patients in one clinic in Santo Domingo. The data are presented in the context of a review of the TDR literature from Latin America and the Caribbean. Genotype testing was successfully performed on 103 treatment-naive adults planning to initiate antiretroviral therapy; the World Health Organization (WHO) list of surveillance drug resistance mutations (SDRM) was used to determine the presence of TDR mutations. WHO SDRM were identified in eight patients (7.8%); none had received sdNVP. There were no significant differences in epidemiologic or clinical variables between those with or without WHO SDRM. The prevalence of WHO SDRM was 1.0% and 6.8% for nucleoside reverse transcriptase inhibitors and nonnucleoside reverse transcriptase inhibitors, respectively. No WHO SDRMs for protease inhibitors were identified. Among 12 studies of TDR in the region with a sample size of at least 100 subjects, the reported prevalence of SDRM ranged from 2.8% to 8.1%. The most commonly identified SDRM was K103N. This information adds to our understanding of the epidemiology of TDR in the region and the possible role such mutations could play in undermining first-line treatment. Ongoing surveillance is clearly needed to better understand the TDR phenomenon in the Caribbean.

A public-health approach to site-specific formulary management: addressing deficient drug supplies in Malawi†

Maintaining a well-stocked dispensary at a private non-profit clinic in a developing country can often be challenging due to limited financial and human resources. Organizations face frequent drug shortages, excesses of unnecessary medications and potentially inappropriate international donations. To promote adherence to international recommendations and enable targeted requests for international drug donations, this paper describes a process using a public-health approach to create a site-specific pharmacy formulary in a resource-poor setting using the World Health Organization's (WHO) Model List of Essential Medicines ('Model List'). The study site was a Malawian-run non-profit private clinic serving over 3000 people annually. The organization focuses on providing community support for orphans from the HIV/AIDS crisis in sub-Saharan Africa. While using the Model List as a backbone, we incorporated the clinic's drug inventory, patient needs, clinician prescribing patterns, and the country's national drug list into the final formulary. After analyzing site-specific factors, we determined which WHO Model List therapeutic classes were necessary for the clinic to address in the final formulary. Of the drug products currently available in the inventory, 65.6% were expired, 29.8% of which were international donations. After removing expired medications from the inventory, seven Model List priority categories remained unaddressed by the clinic's initial inventory. Based on the results of a structured needs assessment, 54 products were selected for the final simplified formulary. Conscious selection of pharmaceuticals, resulting in a systematic formulary for drug distribution management, is critical so that a clinic can focus on procuring and prescribing the most needed medications. This selection process using the WHO Model List and a public-health approach to drug management could serve as a private clinic model for pharmaceutical optimization and targeted international drug donations in sub-Saharan Africa and other resource limited settings.

Malaria rapid diagnostic kits: quality of packaging, design and labelling of boxes and components and readability and accuracy of information inserts

BackgroundThe present study assessed malaria RDT kits for adequate and correct packaging, design and labelling of boxes and components. Information inserts were studied for readability and accuracy of information.MethodsCriteria for packaging, design, labelling and information were compiled from Directive 98/79 of the European Community (EC), relevant World Health Organization (WHO) documents and studies on end-users' performance of RDTs. Typography and readability level (Flesch-Kincaid grade level) were assessed.ResultsForty-two RDT kits from 22 manufacturers were assessed, 35 of which had evidence of good manufacturing practice according to available information (i.e. CE-label affixed or inclusion in the WHO list of ISO13485:2003 certified manufacturers). Shortcomings in devices were (i) insufficient place for writing sample identification (n = 40) and (ii) ambiguous labelling of the reading window (n = 6). Buffer vial labels were lacking essential information (n = 24) or were of poor quality (n = 16). Information inserts had elevated readability levels (median Flesch Kincaid grade 8.9, range 7.1 - 12.9) and user-unfriendly typography (median font size 8, range 5 - 10). Inadequacies included (i) no referral to biosafety (n = 18), (ii) critical differences between depicted and real devices (n = 8), (iii) figures with unrealistic colours (n = 4), (iv) incomplete information about RDT line interpretations (n = 31) and no data on test characteristics (n = 8). Other problems included (i) kit names that referred to Plasmodium vivax although targeting a pan-species Plasmodium antigen (n = 4), (ii) not stating the identity of the pan-species antigen (n = 2) and (iii) slight but numerous differences in names displayed on boxes, device packages and information inserts. Three CE labelled RDT kits produced outside the EC had no authorized representative affixed and the shape and relative dimensions of the CE symbol affixed did not comply with the Directive 98/79/EC. Overall, RDTs with evidence of GMP scored better compared to those without but inadequacies were observed in both groups.ConclusionOverall, malaria RDTs showed shortcomings in quality of construction, design and labelling of boxes, device packages, devices and buffers. Information inserts were difficult to read and lacked relevant information.

The Dread Disease: Cancer in the Developing World

The triumvirate of HIV/AIDS, tuberculosis, and malaria have dominated our public health focus in the developing world. Having claimed millions of lives, these infectious diseases have prompted a large-scale response. Concomitant with these efforts has been a burgeoning bioethics literature examining global health and distributive justice. A scholarly wasteland only a decade ago, there is now a growing and rich literature that aims to unpack our moral obligations when it comes to diseases that affect the majority of the world (many living in absolute poverty). Now, added to the persistent challenges posed by infectious diseases is the growing burden of diseases such as cancer, which disproportionately affect developing nations. The rates of noncommunicable chronic diseases, including cancer, continue to increase in low-income countries. (1) Recent estimates suggest that the case fatality from cancer may be as high as 74.5 percent in low-income countries, compared to 46.3 percent in high-income countries. (2) Survival rates for some cancers, such as testicular and breast cancers, have been positively related to country income. (3) Additionally, low education levels, poor health literacy, and advanced presentation of different cancers lead to further difficulties for people in developing countries. The disparity between cancer resource allocation in lower and higher income countries is stark--about 5 percent of total global funds dedicated to cancer are spent in developing countries. (4) Together with an estimate that 80 percent of disability-adjusted life years lost to cancer worldwide occur in developing countries, (5) a renewed focus on solutions to cancer care in resource-poor settings is past due. Disparities in treatment and survival outcomes are perpetuated by a lack of adequate evidence-based guidelines and treatment algorithms for cost-effective cancer care in developing countries. (6) Most countries have not implemented effective national control strategies that can save lives. (7) Promising models of cancer control in lower- and middle-income country health systems exist, however, and there has already been some discussion of established models in Mexico and Colombia, which both have national insurance plans, and of nascent scale-up efforts ongoing in Rwanda, Malawi, and Haiti. (8) At the heart of scaling up cancer care in resource-poor settings is the pervading assumption that cancer care cannot be provided efficiently or equitably. There are least two problems with this assumption. First, a more generalized version of this assumption has been disproved; there are examples of successfully scaled-up HIV/AIDS and tuberculosis treatment programs in resource-poor settings. (9) Second, the assumption that meaningful cancer care is not feasible in lower-income countries imparts a particular view of reality that reinforces inequity. As John Seffrin of the American Cancer Society has forcefully pointed out, global cancer disparities illustrate a collective failure to actualize the universal human right to access an adequate standard of health, and these disparities in cancer care and mortality demonstrate some of the most glaring social inequalities in health. (10) CanTreat International, also known as the Informal Working Group on Cancer Treatment in Developing Countries, recently highlighted three key lessons learned from the HIV/ AIDS movement that may be applicable to cancer care. (11) First, access to cancer treatment should be mandatory. The World Health Organization's current list of essential chemotherapies is a start in this direction. Second, cancer control needs to be mainstreamed into comprehensive health systems along with ways to provide high-quality care in order to detect and address cancer effectively. Third, advocacy and education are essential, including efforts to define public health priorities and treat cancers within the existing health system to continue to improve cancer interventions and the health system as a whole. …

Odontogenic Myxoma in an 8-Year-Old Labrador Retriever Dog

Odontogenic myxoma (OM) was diagnosed in an 8-year-old Labrador Retriever dog with an ulcerohemorrhagic mass located on the caudal area of the right maxillary gingiva. The neoplasm was characterized by a low mitotic index and moderate numbers of spindle, stellate, and round cells that were sparsely distributed in an alcian blue reactive myxomatous matrix. Individual neoplastic cells were characterized by small amounts of faintly eosinophilic staining cytoplasm, prominent nucleoli, and stippled amphophilic staining chromatin that was immunoreactive for vimentin but negative for cytokeratin and actin. To the authors' knowledge, this is the first reported case of canine OM from North America, and it shares histomorphologic and histochemical features with 3 other cases reported in dogs elsewhere. Whereas, a literature review suggests untreated canine OM is insidious and locally aggressive, the prognosis in the present dog remains unknown. These findings support previous recommendations for inclusion of canine OM on the World Health Organization list of odontogenic tumors.

Commentary: Will generic drug stores improve access to essential medicines for the poor in India?

Policymakers in developing countries are challenged to increase the availability and affordability of essential medicines. To improve access to medicines, the Government of India recently opened Generic Drug Stores in a few public facilities. These stores sell generic medicines manufactured by the public sector manufacturers. The prices are lower than market price. We examine the premise of these stores; where will they fit in the landscape. What can be learned from their early operation and problems encountered? Will selling a small number of generic medicines at public hospitals really improve access to medicines for poor populations? Poor patients are intended to receive medicines free of charge at public facilities. Generic drugs are typically less expensive than brand-name drugs and contain the same active ingredient as the original brand name product.1 Thus generic medicines may be an affordable alternatives to more costly, patented brand name versions of the product.2 World Health Organization's (WHO) essential medicines list is based on generic medicines.3 In most OECD countries, generic medicines are promoted by competition-enhancing policies operating through health-care reimbursements to contain expenditures and encourage efficient use of resources.4 India is well known for its prolific pharmaceutical industry that offers low-cost generics to the world. At home India faces the challenge of equal access to affordable and quality essential medicines for its own people.5 Despite pharmaceutical industry growth in the last two decades, access to essential medicines remains

Development of and Access to Products for Neglected Diseases

IntroductionPrior research on neglected disease drug development suggested inadequate funding was responsible for relatively few new approvals. In response, significantly more resources have been allocated towards development of drugs targeting neglected diseases. Our objective was to reassess drug development between1975 and 1999, evaluate progress in neglected disease drug development since 2000, and explain how increased numbers of approvals are a necessary but insufficient condition to improving access.MethodsTo assess numbers of approvals targeting neglected diseases, we employed two distinct methodologies: First, to revisit numbers published in Trouiller et al. (2002) we used their method to count marketed new chemical entities (NCEs) between 1975 and 1999. Second, using the G-Finder report as a benchmark, we identified which diseases are currently considered “neglected” to tally approvals in the 1975–1999 and 2000–2009 periods. Searching PharmaProjects and IMS R&D Focus databases as well as websites from numerous drug regulatory agencies, we identified new drug approvals and indications. Also, we examined the World Health Organization's (WHO) Essential Drug List (EDL) to see which drugs and indications were on the list.FindingsUpon recount, using Trouiller et al. methodology, we found that between 1975 and 1999 more NCEs (n = 32) targeting tropical diseases and tuberculosis were approved than reported in Trouiller et al. (n = 16). Using the G-Finder method of defining neglected diseases, we found 46 new drug approvals between 1975 and 1999. WHO included 85% of these drugs on the EDL. In the period 2000 to May 2009, despite much greater funding, only 26 new drugs and vaccines for neglected diseases were marketed. Of these, WHO placed 50% on the EDL.ConclusionsProduct approvals for neglected diseases have increased, though progress has been uneven, with malaria appearing to benefit most in the short run from increased funding, while less success has been booked in other disease categories. Uneven progress suggests funding could be better targeted, particularly with regard to neglected diseases that have hitherto received scant attention. In addition, policymakers should focus on other aspects related to access. Besides drug development, there are the issues of EDL listing, architecture, availability, affordability, and adoption.

Adesão a listas de medicamentos essenciais em municípios de três estados brasileiros

This study compared the Municipal Essential Medicines Lists (REMUME) and examined adherence by prescribers and availability of essential medicines in the health units affiliated with the Unified National Health System (SUS). Data were collected on lists and medicines prescribed to 2,411 patients enrolled consecutively in primary or secondary care services in Brazilian municipalities. Of 5,222 prescribed medicines, 76.4% were present on the REMUME, 76.8% on the National List of Essential Medicines (RENAME), and 63% on the World Health Organization (WHO) list. Among the most frequently prescribed medications, one or more did not belong to the respective REMUME. Of all medicines prescribed, 76.1% were available in the inspected facilities; for essential medicines, the availability increased to 88.1%. Prescription in disagreement with the REMUME may result from the unavailability of medicines in the inspected facilities or the lists' inadequacy for the level of care.

Evaluation of Rational Use of Medications in the United States

Rational medication use means taking medication appropriately for curing and relieving the symptoms of disease on the basis of evidence and sound judgment. We compare US policy experience on rational use of medications with the World Health Organization (WHO) list of interventions designed to promote such use. Current US performance and educational, managerial, and regulatory interventions to improve it are discussed. We conclude that, while most of the WHO guidelines for rational medication use are practiced in some form in one or more of the various US health care subsystems today, overall performance based on outcomes is not comparable with that of other industrialized countries. This is due to the absence of a national drug policy, the presence of a few strong stakeholders with committed policy preferences, and the altogether fragmented character of the US state and federal health systems. Practical suggestions are offered as to how the US could improve its overall less-than-optimal policies on rational medication use.

Synthesis, characterization, and immunogenicity in mice of Shigella sonnei O-specific oligosaccharide-core-protein conjugates

Shigellosis, an enteric disease, is on the World Health Organization's priority prevention list. In one study, the Shigella sonnei O-specific polysaccharide (O-SP)-protein conjugate showed 72% protection against disease in Israeli army recruits exposed to high rates (8-14%) of infection. The protection was related to vaccine-induced IgG anti-O-SP levels. Synthetic oligosaccharides of Shigella dysenteriae type 1, bound by their reducing ends to a carrier protein ("sun"-type configuration), induced significantly higher antibody levels than the native O-SP bound to protein by multiple-point attachments ("lattice"-type configuration). Attempts to synthesize the S. sonnei O-SP based oligosaccharides were not successful. Here, we describe the isolation, characterization, and conjugation of low-molecular-mass O-SP-core (O-SPC) fragments. The O-SPC fragments were bound by their reducing ends similar to the preparation of the synthetic S. dysenteriae type 1 conjugates. The O-SPC conjugates used oxime linkages between the terminal Kdo residues at the reducing ends of the S. sonnei saccharides and aminooxy linkers bound to BSA or a recombinant diphtheria toxin. The coupling reaction was carried out at a neutral pH and room temperature. IgG antibody levels induced in young outbred mice by the S. sonnei O-SPC conjugates were significantly higher then those elicited by the O-SP conjugates. Accordingly, we propose to evaluate clinically these conjugates.

International Issues: Neurology training in Pakistan

Pakistan is a developing country rich in ethnic and cultural diversity in its four provinces. It ranks sixth on the World Health Organization (WHO) list of high disease burden countries. The present national infrastructure of health facilities is equipped with 945 hospitals, 4,755 dispensaries, 562 rural health centers, and 5,349 basic health units.1 There are 1,452 patients for every available bed, which is far behind the country requirements.1 Although the total number of registered doctors in Pakistan has increased considerably from 83,682 in 1998 to 127,859 in 2007, there is still only one doctor available for every 1,254 patients and one nurse available for every 2,671 patients, which is below the international recommended ratio.1 The adult literacy rate in Pakistan is 52%.2 The current number of trained neurologists in the country is particularly low. There are only an estimated 85 consultant neurologists3 in a population of 150 million. Nevertheless, this figure reflects a significant growth in neurology in the past few decades. Neurology has grown rapidly from an almost nonexistent discipline approximately 50 years ago.3 In some ways, this rate of progress is akin to the way in which neurology gained its roots in the United States, where it lagged almost a century behind other disciplines in the 1860s.4 Figure Aga Khan University Hospital Reprinted with permission. Dr. Munawwar Hayat established the first department of clinical neurology in Pakistan at King Edward Medical College and Mayo Hospital in Lahore in the late 1960s. In the early 1970s, Dr. Akhtar Ahmed and Dr. Zaki Hussain jointly established departments of neurology in Karachi at Civil Hospital and Jinnah Postgraduate Medical Centre.3 Within the subsequent two decades, neurology flourished across the country. Currently there are at least 16 academic neurology departments throughout Pakistan.3 There …

The consolidation of neuroleptic therapy: Janssen, the discovery of haloperidol and its introduction into clinical practice

The discovery of haloperidol at the end of the 1950s constitutes one of the greatest advances of 20th century psychiatry. This antipsychotic drug has their origin in the research process of central analgesic molecules derived from pethidine and methadone, carried out by the Belgian company Janssen Phamaceutica. After the synthesis of phenoperidine, numerous analogues of this compound were studied, and chemists at Janssen took the decision to substitute the propiophenone group for a butyrophenone group. One of these compounds went the R-1625, a stronger agent with specifically neuroleptic properties but lacking morphine-like activity. This substance was synthesized on the 11th February 1958 and received the generic name of haloperidol because of the two halogenated substitutes incorporated into the molecule. Clinical development of haloperidol was conducted, primarily, by psychiatric research team at the University of Liège that confirmed its efficacy in the treatment of various psychiatric disorders such as acute and chronic paranoid psychosis, mania, or chronic treatment-resistant schizophrenia. Under the brand name Haldol ®, haloperidol was licensed and marketed in Belgium in October 1959. The direct and differed consequences of its introduction into the psychiatric practice have been multiple, involving different areas of socio-sanitary reality. Moreover, haloperidol has contributed substantially to the development of biological psychiatry and currently neuroscience, because it made possible the development of new experimental models for predicting the effects of antipsychotics, and allowed the postulate of the firsts biological hypotheses about the schizophrenia etiology. Haloperidol has been included in the World Health Organisation's list of essential medicines.

Psychopharmacological Treatment Options for Global Child and Adolescent Mental Health: The WHO Essential Medicines Lists

Mental disorders frequently start in childhood and adolescence, and many continue across the life span, leading to substantial morbidity and increased mortality. Effective interventions for child- and adolescent-onset mental disorders are available and psychopharmacological treatments are indicated for many diagnoses and for some significantly impairing symptoms. Globally, psychopharmacological treatments and national formulary decisions are influenced by the World Health Organization's (WHO) Model List of Essential Medicines (EML), which was recently updated to identify those medications deemed necessary for clinical care of children.

Surveillance of transmitted HIV drug resistance in the Manzini-Mbabane corridor, Swaziland, in 2006

BackgroundIn resource-limited settings where anti-retroviral treatment (ART) is being scaled-up, the World Health Organization (WHO) recommends the surveillance of transmitted HIV drug resistance (HIVDR). We used the WHO's HIVDR threshold survey method to assess transmitted HIVDR in three antenatal clinic (ANC) sites along the corridor between the two most populous cities in Swaziland, where ART was introduced in 2003.MethodsFrom July–August 2006, remnant sera were aliquoted from HIV serosurvey specimens collected from 70 primagravidas <25 years old attending ANC during the national HIV serosurvey. Genotyping was performed at the National Institute for Communicable Diseases, South Africa. Transmitted resistance was defined by the WHO's surveillance list of mutations. HIVDR prevalence was categorized using the WHO's threshold survey binomial sequential sampling method.ResultsAmong the 70 eligible specimens, 61 were sequenced – 60 (98%) were identified as subtype C and one as subtype B. No major nucleoside or non-nucleoside reverse transcriptase inhibitor mutations occurred among the first 34 consecutive specimens, which supported a transmitted resistance categorization to these drug classes as <5%. One protease inhibitor mutation, M46I, was seen among the first 44 specimens, supporting a categorization of PI resistance as <5%.ConclusionOur survey indicates that prevalence of transmitted HIVDR among recently infected pregnant women along the Manzini-Mbabane corridor is low (<5%). Surveys will be carried out in this area biannually and may be extended to other areas. Surveys for transmitted resistance make up one element among a spectrum of activities to assess and support minimization of HIVDR.

Components of Health Promoting Schools in Ugandan primary schools: a pilot study

Health Promoting Schools (HPSs) represent key settings through which health can be improved. The World Health Organisation (WHO) has provided component indicators but data on the degree of coverage of these key components of HPSs in many countries are limited. The aim of this pilot study was to determine whether and to what extent information on the components of HPSs in Ugandan primary schools could be generated using focus group discussions (FGD) as well as through observational data. Four schools (two rural and two urban) were randomly selected from the sampling frame of 18 rural and 76 urban government-aided primary schools in Mbale District, Uganda. Focus group discussions (FGDs) involving teachers, parents and pupils were held at each school. Indicators of HPSs were also observed and recorded at each of the selected schools. A scoring system was devised based on the number of positive attributes derived from the WHO list of component indicators. Descriptive analysis from FGDs and observational data was also undertaken. Overall, the urban schools had a higher number of positive observations than rural schools for HPS indicators with some marked variation between urban and rural schools for specific indicators. This pilot study provided data to show that coverage of HPS components by different schools could be successfully evaluated using FGD and observational findings. Those strengths and shortcomings identified within and between the four schools necessitate further exploration with a larger scale study.

The International Association for Hospice and Palliative Care List of Essential Medicines for Palliative Care

The World Health Organization (WHO) requested that the International Association for Hospice and Palliative Care (IAHPC) develop a list of essential drugs for palliative care to be included in the WHO list of essential drugs. This report describes the process by which this specialized list was developed and the outcomes of that process.

The World Health Organization's Essential Medicines List:

The World Health Organization's Essential Medicines List:

The International Association for Hospice and Palliative Care List of Essential Medicines for Palliative Care

The World Health Organization (WHO) requested that the International Association for Hospice and Palliative Care (IAHPC) develop a list of essential drugs for palliative care to be included in the WHO list of essential drugs. This report describes the process by which this specialized list was developed and the outcomes of that process.

Buprenorphine Use: The International Experience

The confluence of the heroin injection epidemic and the human immunodeficiency virus (HIV) infection epidemic has increased the call for expanded access to effective treatments for both conditions. Buprenorphine and methadone are now listed on the World Health Organization's Model Essential Drugs List. In France, which has the most extensive experience, buprenorphine has been associated with a dramatic decrease in deaths due to overdose, and buprenorphine diversion appears to be associated with inadequate dosage, social vulnerability, and prescriptions from multiple providers. Other treatment models (in the United States, Australia, Germany, and Italy) and buprenorphine use in specific populations are also reviewed in the present article. In countries experiencing a dual epidemic of heroin use and HIV infection, such as former states of the Soviet Union and other eastern European and Asian countries, access to buprenorphine and methadone may be one potential tool for reducing the spread of HIV infection among injection drug users and for better engaging them in medical care.

Role of follow-on drugs and indications on the WHO Essential Drug List

The World Health Organization's Essential Drug List (EDL) contains first-in-class drugs and subsequent class entrants (follow-on drugs) deemed necessary to combat diseases prevalent throughout the world, with a special emphasis on developing nations. The EDL also includes originally approved and follow-on indications. There are opposing views regarding the value of follow-on drugs and indications. Critics suggest many follow-on drugs and indications offer little or no benefit to patients. Advocates counter that follow-on drugs offer advantages in terms of improved effectiveness, compliance and patient satisfaction. In order to inform this debate on the value of follow-on drugs and indications we examined the numbers of follow-on drugs on the EDL and the extent to which follow-on indications are recommended. We identified all 312 drugs on the 14th edition of the EDL, omitting 72 non-pharmaceutical entities. For the 240 pharmaceutical entities we ascertained whether the Food and Drug Administration (FDA) had approved them, and, if so, when each was approved. We chose a validated therapeutic classification system - the United States Pharmacopeia's Model Guidelines for Medicare formulary management - in order to distinguish first-in-class and follow-on drugs on the EDL. Specifically, we selected the formulary key drug type as our benchmark therapeutic class. We assigned each EDL drug to a formulary key drug type. We defined first-in-class drugs as the first in each formulary key drug type, and follow-on drugs as all other drugs in each formulary key drug type. We identified follow-on indications by comparing WHO-listed indications with the original approved indication(s) by the FDA. Finally, we examined the therapeutic rating (priority vs. standard) given by the FDA to follow-on drugs on the EDL. Sixty-three per cent of the EDL drugs were follow-ons; 15% of the indications were follow-on indications. Fourteen drugs were listed in multiple WHO (sub) groupings; and 49% of follow-on drugs were given a priority rating by the FDA. In light of the fact that the EDL only includes drugs and indications deemed essential, the large number of follow-on drugs, follow-on indications, and priority-rated follow-on drugs on the EDL suggest their importance. From a public policy perspective, it may prove counterproductive to erect hurdles that impede follow-on research and development.