Publication: The Epidemiological Impact of an HIV/AIDS Vaccine in Developing Countries
Loading...
Published
2002-03
ISSN
Date
2013-08-06
Editor(s)
Abstract
Many people see an effective preventive AIDS vaccine as the best solution to the HIV/AIDS pandemic. Ten years ago many scientists had hoped that a vaccine would be available by now. Most scientists are still optimistic that vaccines will be developed and many candidates are being tested. Strategies to implement HIV/AIDS vaccination need to be developed to be ready when vaccines do become available. The nature of those programs will depend on the characteristics of each vaccine. How much does it cost? How effective is it? How long does protection last? The answers to these and other questions will help determine issues such as: What will be the impact of the vaccine on the epidemic? Who should be vaccinated? Will an AIDS vaccine be more cost-effective than other prevention measures? Will other measures still be necessary? What will happen to the epidemic if vaccination leads to riskier behavior? How much funding will be needed? The authors use two computer simulation models to investigate the effects of various vaccine characteristics and implementation strategies on the impact and cost-effectiveness of vaccines in different contexts. A simulation model is applied to data from rural Zimbabwe and the iwgAIDS model is applied to Kampala (Uganda) and Thailand. The models are used to investigate the effects of efficacy, duration, cost, and type of protection on impact and cost-effectiveness. The models also show the merits of targeting public subsidies to various population groups: all adults, teenagers, high-risk groups, and women of reproductive age. The impact of vaccines on the epidemic is compared with the impact of other prevention interventions such as condom use and behavior change. Finally, the models are used to explore the extent with which behavioral reversals may erode the positive benefits of the vaccine. A highly effective, long-lasting, inexpensive vaccine would be ideal and could make a major contribution in controlling the HIV/AIDS pandemic. But vaccines that do not attain this ideal can still be useful. A vaccine with 50 percent efficacy and 10 years duration supplied to 65 percent of all adults could reduce HIV incidence by 25 to 60 percent, depending on the context and stage of the epidemic. Better efficacy and longer duration would provide even more impact. Programs focused on teenagers or high-risk populations have less overall impact but would provide significant benefits at much less cost than those reaching all adults. Behavioral reversals could erode much of the benefits of vaccination programs so it will be important to combine vaccination with continued messages about the importance of safe behaviors. The cost of the vaccines is not known at this time. At a cost of $10 or $20 per person vaccinated, the cost per infection averted would be as low or lower than other prevention interventions. Higher costs for the vaccines and the need for many booster shots could reduce the cost-effectiveness significantly.
Link to Data Set
Citation
“Stover, John; Garnett, Geoff P.; Seitz, Steve; Forsythe, Steven. 2002. The Epidemiological Impact of an HIV/AIDS Vaccine in Developing Countries. Policy Research Working Paper;No.2811. © World Bank. http://hdl.handle.net/10986/14818 License: CC BY 3.0 IGO.”
Associated URLs
Associated content
Other publications in this report series
Publication Global Poverty Revisited Using 2021 PPPs and New Data on Consumption(Washington, DC: World Bank, 2025-06-05)Recent improvements in survey methodologies have increased measured consumption in many low- and lower-middle-income countries that now collect a more comprehensive measure of household consumption. Faced with such methodological changes, countries have frequently revised upward their national poverty lines to make them appropriate for the new measures of consumption. This in turn affects the World Bank’s global poverty lines when they are periodically revised. The international poverty line, which is based on the typical poverty line in low-income countries, increases by around 40 percent to $3.00 when the more recent national poverty lines as well as the 2021 purchasing power parities are incorporated. The net impact of the changes in international prices, the poverty line, and new survey data (including new data for India) is an increase in global extreme poverty by some 125 million people in 2022, and a significant shift of poverty away from South Asia and toward Sub-Saharan Africa. The changes at higher poverty lines, which are more relevant to middle-income countries, are mixed.Publication The Macroeconomic Implications of Climate Change Impacts and Adaptation Options(Washington, DC: World Bank, 2025-05-29)Estimating the macroeconomic implications of climate change impacts and adaptation options is a topic of intense research. This paper presents a framework in the World Bank's macrostructural model to assess climate-related damages. This approach has been used in many Country Climate and Development Reports, a World Bank diagnostic that identifies priorities to ensure continued development in spite of climate change and climate policy objectives. The methodology captures a set of impact channels through which climate change affects the economy by (1) connecting a set of biophysical models to the macroeconomic model and (2) exploring a set of development and climate scenarios. The paper summarizes the results for five countries, highlighting the sources and magnitudes of their vulnerability --- with estimated gross domestic product losses in 2050 exceeding 10 percent of gross domestic product in some countries and scenarios, although only a small set of impact channels is included. The paper also presents estimates of the macroeconomic gains from sector-level adaptation interventions, considering their upfront costs and avoided climate impacts and finding significant net gross domestic product gains from adaptation opportunities identified in the Country Climate and Development Reports. Finally, the paper discusses the limits of current modeling approaches, and their complementarity with empirical approaches based on historical data series. The integrated modeling approach proposed in this paper can inform policymakers as they make proactive decisions on climate change adaptation and resilience.Publication Gender Gaps in the Performance of Small Firms: Evidence from Urban Peru(Washington, DC: World Bank, 2025-09-23)This paper estimates the gender gap in the performance of firms in Peru using representative data on both formal and informal firms. On average, informal female-led firms have lower sales, labor productivity, and profits compared to their male-led counterparts, with differences more pronounced when controlling for observable determinants of firm performance. However, gender gaps are only significant at the bottom of the performance distribution of informal firms, and these gaps disappear at the top of the distribution of informal firms and for formal firms. Possible explanations for the performance gaps at the bottom of the distribution include the higher likelihood of small, female-led firms being home-based, which is linked to lower profits, and their concentration in less profitable sectors. The paper provides suggestive evidence that household responsibilities play a key role in explaining the gender gap in firm performance among informal firms. Therefore, policies that promote access to care services or foster a more equal distribution of household activities may reduce gender productivity gaps and allow for a more efficient allocation of resources.Publication The Exposure of Workers to Artificial Intelligence in Low- and Middle-Income Countries(Washington, DC: World Bank, 2025-02-05)Research on the labor market implications of artificial intelligence has focused principally on high-income countries. This paper analyzes this issue using microdata from a large set of low- and middle-income countries, applying a measure of potential artificial intelligence occupational exposure to a harmonized set of labor force surveys for 25 countries, covering a population of 3.5 billion people. The approach advances work by using harmonized microdata at the level of individual workers, which allows for a multivariate analysis of factors associated with exposure. Additionally, unlike earlier papers, the paper uses highly detailed (4 digit) occupation codes, which provide a more reliable mapping of artificial intelligence exposure to occupation. Results within countries, show that artificial intelligence exposure is higher for women, urban workers, and those with higher education. Exposure decreases by country income level, with high exposure for just 12 percent of workers in low-income countries and 15 percent of workers in lower-middle-income countries. Furthermore, lack of access to electricity limits effective exposure in low-income countries. These results suggest that for developing countries, and in particular low-income countries, the labor market impacts of artificial intelligence will be more limited than in high-income countries. While greater exposure to artificial intelligence indicates larger potential for future changes in certain occupations, it does not equate to job loss, as it could result in augmentation of worker productivity, automation of some tasks, or both.Publication Geopolitical Risks and Trade(Washington, DC: World Bank, 2025-09-23)This paper studies the impact of geopolitical risks on international trade, using the Geopolitical Risk (GPR) index of Caldara and Iacoviello (2022) and an empirical gravity model. The impact of spikes in geopolitical risk on trade is negative, strong, and heterogeneous across sectors. The findings show that increases in geopolitical risk reduce trade by about 30 to 40 percent. These effects are equivalent to an increase of global tariffs of up to 14 percent. Services trade is most vulnerable to geopolitical risks, followed by agriculture, and the impact on manufacturing trade is moderate. These negative effects are partially mitigated by cultural and geographic proximity, as well as by the presence of trade agreements.
Journal
Journal Volume
Journal Issue
Collections
Related items
Showing items related by metadata.
Publication The Changing HIV/AIDS Landscape : Selected Papers for the World Bank's Agenda for Action in Africa, 2007-2011(World Bank, 2009)The HIV/AIDS pandemic in Sub-Saharan Africa remains a long-term development challenge for the region. Nearly 12 million African children have been orphaned as a result of the disease, and 22.5 million people in Africa 61 percent of them women live with HIV. The hyperepidemics in Southern Africa have diluted poverty reduction efforts and in several countries substantially reduced life expectancy. The critical need to address this development problem is reflected in the sixth Millennium Development Goal (MDG), which seeks to halt and begin to reverse the spread of HIV/AIDS by 2015 and to make access to treatment for HIV/AIDS universal for all those who need it by 2010. With Sub-Saharan Africa representing nearly two-thirds of those living with HIV globally, and the fact that human development indicators of several countries in the region lag far behind the rest of the world, prospects for Sub-Saharan Africa reaching any of the MDG goals will require a sustained response to HIV/AIDS. Reversing the spread of HIV/AIDS is closely linked to combating other major diseases referenced in sixth MDG, promoting gender equality (MDG 3), reducing child mortality (MDG 4) and improving maternal health (MDG 5).Publication The Potential Demand for and Strategic Use of an HIV-1 Vaccine in Southern India(World Bank, Washington, DC, 2003-05)Even a modestly effective HIV-1 vaccine would be highly useful in India and could avoid millions of deaths. How should such a vaccine be introduced? Based on evidence of adoption of other vaccines in India, current levels of spending on them and coverage of prevention programs targeting both high- and low-risk groups, Seshadri, Subramaniyam, and Jha assess the potential demand for and strategic use of an HIV-1 vaccine in the four southern Indian states of Andhra Pradesh, Karnataka, Maharashtra, and Tamil Nadu. The authors also discuss potential strategies for delivery of the vaccine, prioritization for vaccination, and the political economy of such a vaccine in India. Assuming a vaccine cost of $10 a dose and including estimated delivery costs, the total cost of vaccinating 21.6 million adolescents 11-14 years of age and 1 percent of adults would be Rs. 12.25 billion (US$ 245 million). To maintain the vaccination rate in the 11-14 year old cohort, an additional 6.77 million in that age range would have to be vaccinated each year, at a vaccine cost of Rs. 3.39 billion (US$ 67.5 million). An HIV-1 vaccine will greatly reduce HIV/AIDS in India, but it will not be a panacea. There will be a continued need for effective prevention programs to guard against behavior reversals or an imperfect vaccine. Key inputs for prevention, immunization, and treatment programs such as identification of various groups that could be immunized (vulnerable groups or general populations), strengthened surveillance, capacity building, operations research, and evaluation at local levels will continue to require intensive support.Publication The Epidemiological Impact of an HIV Vaccine on the HIV/AIDS Epidemic in Southern India(World Bank, Washington, DC, 2003-02)The potential epidemiological impact of preventive HIV vaccines on the HIV epidemic in Southern India is examined using a mathematical deterministic dynamic compartmental model. Various assumptions about the degree of protection offered by such a vaccine, the extent of immunological response of those vaccinated, and the duration of protection afforded are explored. Alternative targeting strategies for HIV vaccination are simulated and compared with the impact of conventional prevention interventions in high-risk groups and the general population. The impact of disinhibition (increased risk behavior due to the presence of a vaccine) is also considered. Vaccines that convey a high degree of protection in a share of or all of those immunized and that convey life-long immunity are the most effective in curbing the HIV epidemic. Vaccines that convey less than complete protection may also have substantial public health impact, but disinhibition can easily undo their effects and they should be used combined with conventional prevention efforts. Conventional interventions that target commercial sex workers and their clients to increase condom use can also be highly effective and can be implemented immediately, before the arrival of vaccines.Publication The New HIV/AIDS Program in Peru : The Role of Prioritizing and Budgeting for Results(World Bank Group, Washington, DC, 2015-01)This study aims to evaluate and develop recommendations on how the HIV/AIDS program in Peru can achieve better Value for Money. In Peru, the HIV epidemic concentrates mostly among men who have sex with men (MSM), with AIDS being the first cause of death for men ages 30-49 in 2010 and the second cause of death for women aged 25-34 (BOD, 2013). UNAIDS (2013) estimates there were 76,000 people living with HIV/AIDS (PLWA) in 2012, and this study estimates 67,000 PLWA in 2013. The Ministry of Health reports that 27,502 PLWA currently receive ART, a 43-48 percent coverage of eligible people, and 66 percent coverage of all diagnosed eligible individuals (WHO, 2013 guidelines). In 2011, there was a transition from international to domestic public funding, which increased from US$17.7 million in 2005-10 to US$57.8 million in 2011-13. The main achievements of the Peru HIV/AIDS program to date include: (i) collaboration with NGOs to provide ART; (ii) free provision of ART; (iii) educating poor women on mother to child HIV transmission; and (iv) access to reduced ARV prices through the PAHO Drug Fund. Major challenges include: (i) limited testing and laboratory capacity in the provinces; (ii) less than half of the budget is allocated to high-risk groups; (iii) wage bill issued by other programs and; (iv) limited number of community health workers (CHWs) for IEC.Publication HIV/AIDS(Washington, DC, 2003-10)The epidemic spread of HIV/AIDS has been ferocious, posing a great threat, not only to public health, but to social sectors, and to development itself, while the fiscal cost of HIV/AIDS is significant as well. A set of effective prevention interventions include: changing behavior through communication; making the use of condoms, diagnosis, and treatment of sexually transmitted diseases, including counseling and testing, available and affordable; ensuring a safe blood supply; and, preventing parent-to-child transmission. In addition, countries should consider implementing programs to provide cost-effective management of common opportunistic infections. Similarly, community-based, and home-based care should be made available, in addition to traditional hospital care, particularly in countries with a generalized epidemic. Lessons convey the vital need for early action, supported by community participation, targeting the most vulnerable, and prioritizing interventions, while governments should be committed to its prevention, control, and funding. Additionally, nongovernmental organizations' participation plays a decisive role against the epidemic spread, in their capacity for social mobilization, and in reaching marginal groups.
Users also downloaded
Showing related downloaded files
Publication Business Ready 2024(Washington, DC: World Bank, 2024-10-03)Business Ready (B-READY) is a new World Bank Group corporate flagship report that evaluates the business and investment climate worldwide. It replaces and improves upon the Doing Business project. B-READY provides a comprehensive data set and description of the factors that strengthen the private sector, not only by advancing the interests of individual firms but also by elevating the interests of workers, consumers, potential new enterprises, and the natural environment. This 2024 report introduces a new analytical framework that benchmarks economies based on three pillars: Regulatory Framework, Public Services, and Operational Efficiency. The analysis centers on 10 topics essential for private sector development that correspond to various stages of the life cycle of a firm. The report also offers insights into three cross-cutting themes that are relevant for modern economies: digital adoption, environmental sustainability, and gender. B-READY draws on a robust data collection process that includes specially tailored expert questionnaires and firm-level surveys. The 2024 report, which covers 50 economies, serves as the first in a series that will expand in geographical coverage and refine its methodology over time, supporting reform advocacy, policy guidance, and further analysis and research.Publication The Epidemiological Impact of an HIV Vaccine on the HIV/AIDS Epidemic in Southern India(World Bank, Washington, DC, 2003-02)The potential epidemiological impact of preventive HIV vaccines on the HIV epidemic in Southern India is examined using a mathematical deterministic dynamic compartmental model. Various assumptions about the degree of protection offered by such a vaccine, the extent of immunological response of those vaccinated, and the duration of protection afforded are explored. Alternative targeting strategies for HIV vaccination are simulated and compared with the impact of conventional prevention interventions in high-risk groups and the general population. The impact of disinhibition (increased risk behavior due to the presence of a vaccine) is also considered. Vaccines that convey a high degree of protection in a share of or all of those immunized and that convey life-long immunity are the most effective in curbing the HIV epidemic. Vaccines that convey less than complete protection may also have substantial public health impact, but disinhibition can easily undo their effects and they should be used combined with conventional prevention efforts. Conventional interventions that target commercial sex workers and their clients to increase condom use can also be highly effective and can be implemented immediately, before the arrival of vaccines.Publication Commodity Markets Outlook, April 2025(Washington, DC: World Bank, 2025-04-29)Commodity prices are set to fall sharply this year, by about 12 percent overall, as weakening global economic growth weighs on demand. In 2026, commodity prices are projected to reach a six-year low. Oil prices are expected to exert substantial downward pressure on the aggregate commodity index in 2025, as a marked slowdown in global oil consumption coincides with expanding supply. The anticipated commodity price softening is broad-based, however, with more than half of the commodities in the forecast set to decrease this year, many by more than 10 percent. The latest shocks to hit commodity markets extend a so far tumultuous decade, marked by the highest level of commodity price volatility in at least half a century. Between 2020 and 2024, commodity price swings were frequent and sharp, with knock-on consequences for economic activity and inflation. In the next two years, commodity prices are expected to put downward pressure on global inflation. Risks to the commodity price projections are tilted to the downside. A sharper-than-expected slowdown in global growth—driven by worsening trade relations or a prolonged tightening of financial conditions—could further depress commodity demand, especially for industrial products. In addition, if OPEC+ fully unwinds its voluntary supply cuts, oil production will far exceed projected consumption. There are also important upside risks to commodity prices—for instance, if geopolitical tensions worsen, threatening oil and gas supplies, or if extreme weather events lead to agricultural and energy price spikes.Publication Latin America and the Caribbean Economic Review, April 2025: Organized Crime and Violence in Latin America and the Caribbean(Washington, DC: World Bank, 2025-04-28)The Latin America and Caribbean region faces a very different outlook from what was foreseen six months ago. Despite continued progress on reducing inflation, LAC continues to grow more slowly than any other region of the world and increasing its dynamism and job creation potential faces new and daunting challenges. First, higher and more persistent inflation than anticipated in the advanced countries has slowed global interest rate declines which constrains regional monetary authorities’ ability to loosen monetary policy. Second, higher interest payments on debt consume an increasing share of government revenue impeding progress on reducing deficits and creating fiscal space for necessary public investment. Third, rising tariffs have driven up uncertainty around the nature of the global trade order, threaten market access for exports, and call into question the nearshoring project. Fourth, increased return migration will, in some cases, stress local labor markets and dampen remittances. Fifth, organized crime, and the violence that accompanies it continues to expand, reducing the quality of life of citizens, dampening economic growth, and undermining the integrity of public institutions. Progress on the fiscal front, as well as continued productivity related reforms to make the region more able to negotiate a changing environment are needed.Publication Classroom Assessment to Support Foundational Literacy(Washington, DC: World Bank, 2025-03-21)This document focuses primarily on how classroom assessment activities can measure students’ literacy skills as they progress along a learning trajectory towards reading fluently and with comprehension by the end of primary school grades. The document addresses considerations regarding the design and implementation of early grade reading classroom assessment, provides examples of assessment activities from a variety of countries and contexts, and discusses the importance of incorporating classroom assessment practices into teacher training and professional development opportunities for teachers. The structure of the document is as follows. The first section presents definitions and addresses basic questions on classroom assessment. Section 2 covers the intersection between assessment and early grade reading by discussing how learning assessment can measure early grade reading skills following the reading learning trajectory. Section 3 compares some of the most common early grade literacy assessment tools with respect to the early grade reading skills and developmental phases. Section 4 of the document addresses teacher training considerations in developing, scoring, and using early grade reading assessment. Additional issues in assessing reading skills in the classroom and using assessment results to improve teaching and learning are reviewed in section 5. Throughout the document, country cases are presented to demonstrate how assessment activities can be implemented in the classroom in different contexts.