AIDS vaccine research riding high.

News The world in 2050: more crowded, urban and aged The world’s population — with today’s 6.1 billion already more than twice the 1950 figure— is likely to grow by another 3 billion in the next half-century, according to a recently released UN projection. Most of the population growth will occur in the less developed countries of Africa and Asia, despite the staggering death toll of the AIDS epidemic in these countries. In contrast, populations in all but a few industrialized countries will remain stable or even shrink. What’s more, medical progress will allow people to live longer and thus steadily increase the percentage of retirees in the years to come. These are the conclusions ofWorld Population Prospects: the 2000 Revision, the sixteenth round of global demographic estimates and projections made by the UN Population Division since 1950. Altogether, Mr Joseph Chamie, director of the UN Population Division that compiles the population projections, told the Bulletin ‘‘the world’s population will be very different in 50 years. It will be substantially larger, especially in the developing countries, significantly older andmuchmore urbanized.’’ The world’s population is currently growing at a rate of 1.2%, or 77 million people, per year with six countries account- ing for half of the growth: India (21%), China (12%), Pakistan (5%), Nigeria (4%), Bangladesh (4%), and Indonesia (3%). Although fertility rates are coming down in every region and in virtually every country of the world, Chamie points out, by 2050 the overall figure is anticipated to swell to 9.3 billion, and nearly nine of every ten people will be living in a developing country — one out of six in India alone, which will replace China as the most populous nation. Taken together, the population of theworld’s less developed nations is expected to grow from 4.9 billion to 8.1 billion. In sub-Saharan Africa, the number of people could even triple. But this is only one side of the coin. For themore developed countries as a whole, population growth is likely soon to come to a standstill at the current 1.2 billion level, according to the UN projection. Notable exceptions, however, are several industria- lized countries, such as Australia, Canada and the US, that are projected to be at least a third larger by 2050 than they are today. By mid- century the populations of 39 developed countries are likely to be even smaller than today, e.g. Japan and Germany by 14%, Italy and Hungary by 25%, and countries of the former Soviet Union by 30–40%, leading to a shift in balance. Fifty years ago, when Europe claimed about 20% of the world’s population, Africa amounted to just 8%. In 50 years, however, Africa will have three times as many people as Europe, even though AIDS is anticipated to cut Africa’s population growth by 15%. ‘‘The engine that determines these differences is the vast difference in fertility rates (between less developed and industria- lized countries),’’ says Chamie. In virtually all countries of the more developed regions fertility is currently below the replacement level of 2.1 children per woman — the level needed to ensure that a population will replace itself in the long run. Countries with the lowest fertility rates include Bulgaria, China, Spain (all 1.1) and Italy (1.2), while Niger (8.0), Somalia (7.25) and Angola (7.2) top the high-fertility roster. A noteworthy exception among major industrial nations is the US, expected to grow from 283 million today to nearly 400 million at mid-century. By then, the US will be the only developed country among the world’s 20 most populous nations. In 1950, at least half of the top 10 were industrial nations. About 70% of population growth in the US will be due to immigration. Without migration, the populations of more developed regions as a whole would start declining in 2003 rather than in 2025, the UN report notes. But the Earth is not only going to be muchmore crowded: the UN projection also predicts that the industrializedworld—most European countries, plus Australia, Canada, Japan, New Zealand, and the US — will be confronted with an ageing population. Globally, ‘‘wewill see a tripling in the number of people 60 years or older’’, increasing from 606 million today to nearly 2 billion by 2050, says Chamie. In more developed regions, people 60 or over currently constitute about 20% of the population. In 50 years, they will account for 33%. In Europe that figure could even jump to 37%. With fewer people in the workforce and more people living off retirement funds and pensions, an ever older population will represent a major strain for social security systems, Mr Paul Hewitt, project director for the Global Aging Initiative at the Center for Strategic and International Studies, commented to the Bulletin. ‘‘An ageing population is probably the main challenge for the world economy in the next century. Soon the industrial world will face chronic labour shortages and shrinking populations. Retirement as we know it will probably cease to exist in a number of countries,’’ he says. The UN’s Chamie agrees. ‘‘Now is the time to prepare,’’ he says. ‘‘I offer people three pieces of advice: Prepare for your retirement and old age, prepare for your retirement and old age, and prepare for your retirement and old age.’’ n Michael Hagmann, Zurich, Switzerland News Feature AIDS vaccine research riding high The announcement in March that the first AIDS vaccine candidate designed primarily for use in East Africa is entering human trials in Kenya, is just the latest in a series of encouraging events that has marked AIDS vaccine research over the past year or so. Hopes are running high that the current flurry of activity will produce a truly effective vaccine. Some experts, though, still licking the wounds of past disappoint- ments, urge caution. The Kenya vaccine was developed by a team of researchers from the University of Oxford, in the UK, and the University ofNairobi, in Kenya. It is based on the ‘‘clade A’’ variety of HIV, which is responsible for about 60% of HIV infections in East Africa. The Kenya trial is in the first, or Phase 1, stage of human tests and aims to determine the vaccine’s safety. A preliminary human trial was begun last August in Oxford, where the vaccine has been administered to 18 vol- unteers with no adverse effects to date.Work on the vaccine has been coordinated and funded by theNewYork-based International AIDS Vaccine Initiative (IAVI). The vaccine will be given in a two-shot, ‘‘prime-boost’’ regimen. The first, priming, shot consists of HIV genes (naked DNA) injected directly into the vaccine recipient. The second, booster, shot uses a viral vector to carry HIV genes into the recipient. This vector, called ‘‘Modified Vaccinia Ankara’’, is a version of vaccinia, the virus used to make the smallpox vaccine, but modified to prevent it from replicating in human cells. 484 # World Health Organization 2001 Bulletin of the World Health Organization, 2001, 79 (5) The prime-boost approach is all the rage among vaccine researchers at the moment, as it shows good results in monkeys. A US research team from the National Institute of Allergy and Infectious Diseases (NIAID) and Emory University, in Atlanta, Georgia, recently reported that 23 of 24 monkeys given a prime-boost vaccine and then challenged with very high doses of SIV — the monkey version of human HIV — remained alive and well, whereas unvacci- nated controls quickly developed AIDS- related infections. The vaccinated animals were still infected, but had 2000 times lower levels of virus than the controls. Professor Andrew McMichael, head of the Medical Research Council’s human immunology unit at Oxford, where the Kenya vaccine was designed, says: ‘‘The ‘prime-boost’ approach is currently being tested in animal studies on several candidate vaccines which induce cellular immune responses, with or without antibodies. If two or three of these vaccines go all the way to Phase 3, we’ll learn whether or not the approach works. It may be only partial protection. It may only be short-lived. But I think as soon as we get our foot in the door, we can lever it open. At the moment we’ve got nothing.’’ Commenting on the hopes raised by the launch of the Kenya vaccine trial, Dr Jose´ Esparza, coordinator of the WHO/UNAIDS HIV Vaccine Initiative, warns against going overboard: ‘‘I’ve been working in this field for ten years,’’ he commented to the Bulletin. ‘‘So I’m a bit more cautious, and we should try to avoid creating too high expectations. This is just the first step of what could be a long journey’’. Dr Peggy Johnston, director of AIDS vaccine research at the NIAID and, with a US$ 214 million annual budget for AIDS vaccine research and development, by far the largest funder of AIDS vaccine research worldwide, adds: ‘‘We’ve made tremendous strides in identifying several different candidate vaccines that induce good cellular immune responses in animal models. What we don’t know is first of all, if they work in humans; second, if protection lasts; and third, and most important, if vaccinated individuals can still transmit infection. We want a vaccine that not only saves individuals but stops the virus spreading.’’ Johnston says she’d like to see more work on broadly reactive antibody responses. They could prevent initial infection, but ‘‘that’s a nut that hasn’t been cracked yet’’ she says. Meanwhile, AIDS vaccine research, after several years in the doldrums, is on a roll, with funding on an upward spiral and the whole field flush with enthusiasm. The European Union has launched a new AIDS vaccine initiative, Eurovac, and France and Japan have their own programmes, along with the NIAID, IAVI, the Centers for Disease Control and Prevention, and the Walter Reed Army Institute of Research in the US, plus several groups in developing countries, including Brazil, India and South Africa. Pharmaceutical companies, such as Merck, GlaxoSmithKline and Wyeth Lederle, have also returned to the scene. And an African AIDS Vaccine Programme, uniting African researchers, is soon to be launched by WHO and UNAIDS. With AIDS vaccine research burgeon- ing, both the NIAID and WHO see a growing need for coordination, especially for trials in Africa and other developing regions. The NIAID’s Johnston is pressing for international coordination, especially on developing common trial sites, while encouraging healthy competition amongst agencies and vaccine concepts. As for WHO, Esparza says, ‘‘we are an honest broker, bringing industry, agencies and countries together to do the trials, and building capacity for this long-term effort. But we need a system to make decisions, because in the past we have had products and even sites for trials, but no decision to move. The international community should have more to say on moving ahead with trials.’’ These trials, Esparza says, should covermany more types of vaccine than the few currently in the research pipeline. ‘‘Unfortunately, though, many of the labs and agencies are after the same products. This happens in the scientific community. Consensus is reached very quickly because everybody is reading the same scientific articles and following the same paradigms.’’ n Robert Walgate, London A 15-year-old Tanzanian girl in a street in Dar es Salaam, waiting, like countless others, for a vaccine to prevent HIV/AIDS, a too common feature of today’s urban Africa. Ph ot og ra ph G ia co m o Pi ro zz i/U N IC EF 485Bulletin of the World Health Organization, 2001, 79 (5) News WHO News Water and health, hand-in-hand for a day To raise awareness of the connection between water and health, WHOwas chosen as lead agency for World Water Day on 22 March. Scores of events, ranging from Internet-based discussions among students to ice-hockey games, music video releases, and the more traditional seminars and awards, took place in countries around the world. WorldWater Day has been celebrated annually since it was first conceived at the 1992 UN Conference on Environment and Development in Rio de Janeiro. This is the first year that WHO has acted as primary sponsor. ‘‘Access to safe water is a universal need ... and a basic human right,’’ WHO director- general, DrGroHarlemBrundtland, said in a video released on the World Water Day web site (www.worldwaterday.org). More than one billion people — 18% of the world’s population — do not have access to ‘‘improved sources’’ of water and 2.4 billion do not have access to basic sanitation, she noted. Consequently, more than 3 million people die each year from water-related diseases such as diarrhoea and malaria. Millions of others suffer from diseases such as dysentery, which can be transmitted by contaminated water, and trachoma, which is associated with lack of readily accessible water. A lack of clean water is often linked to poverty. ‘‘The absence of a safe water supply contributes to an estimated 80% of disease and death in the developing world,’’ said UN secretary-general Kofi Annan. ‘‘Clean water is a luxury that remains out of the reach of many.’’ A WHO report, Water for Health — Taking Charge, released on World Water Day, recommends several low-tech methods for improving water supplies and health in developing countries. ‘‘Business as usual is no longer an option,’’ Brundtland wrote in the report’s foreword. ‘‘We don’t have enough time to just wait for large infra- structure investments to provide these basic services. Several simple interventions are available.’’ The report recommends chlorination, both in communities and for individual households. In one island country, Maldives, where chlorination was used in wells and rainwater collection tanks, deaths from diarrhoea were eliminated, according to the report. Another recommendation is for use of solar water disinfection, or SODIS, whereby water in plastic bottles is disinfected by exposure to the sun for at least 2 hours. A third recommendation is a change in behaviour. Handwashing with soap, for example, can dramatically lower rates of disease. n Catherine Dold, Boulder, Colorado, USA A day in the life of the world’s anti-TB drive In March, WHO and the Stop TB partner- ship launched a US$ 50 million-a-year initiative to provide free drugs to 10 million tuberculosis patients over the next five years. By 2010, the Global TB Drug Facility, as the initiative is called, aims to reach 45 mil- lion patients in the worst-affected countries. By 2020, it hopes to have prevented 25 million TB deaths and 50 million cases. The new drug facility was launched in the run-up to World TB Day, 24 March, which this year focused on tuberculosis as a human rights issue. In announcing the new facility, WHO director-general Dr Gro Harlem Brundtland said access to treatment and cure was basic to human rights. ‘‘It is shameful that TB patients are still dying of the disease, and inexcusable that less than a quarter of them have access to effective treatment.’’ In its annual report on global tubercu- losis control, also issued in the run-up to World TB Day, WHO estimates that 8.4 million people contracted TB in 1999 — up from 8 million in 1997. The biggest increase in cases since 1997 was in sub- Saharan Africa, which experienced a 20% surge in cases due to the high rates of people co-infected with HIV and TB. About two Collecting water is usually a woman’s job. Pi ct ur e: W H O A sampling of World TB Day events This year’s World TB Day falls on 24 March. It was marked by a series of national and international events coordinated by the partners of the Stop TB partnership. . 16 March, Cape Town, South Africa: Archbishop Desmond Tutu launches World TB Day with the publication of a new report by the Stop TB partnership: A human rights approach to tuberculosis. . 20 March, New York, USA: the medical relief agency Me´decins Sans Frontie`res (MSF) holds a panel discussion, chaired by Pulitzer prize- winning author Laurie Garrett, on Defusing the time bomb: the world’s TB crisis. . 21 March, Washington DC, USA: the [US] National Council for the Elimina- tion of TB and the Stop TB partnership launch the Global TB Drug Facility (see main text) and outline plans to introduce a new bill in the US Congress — the Omnibus Tuberculosis Control Bill 2001 — designed to boost US funding for national and global TB control activities. . 23 March, Brussels, Belgium: the Global Alliance for TB Drug Development releases early research findings from a new study — The pharmaco-economics of TB drug development — which demonstrate the large market potential for a new TB drug that could reduce the treatment period from six to two months. . 23 March, Moscow, Russian Federation: MSF holds a Contagious concert, in which young musicians perform works by composers who suffered from tuberculosis — including Chopin, Liszt, Shostakovitch, and Stravinsky. 486 Bulletin of the World Health Organization, 2001, 79 (5) million people die from TB every year, half a million with concurrent HIV infection. Although TB is curable, only 23% of people with active TB have access to DOTS, formerly an acronym for ‘‘directly observed treatment short-course’’, but now a ‘‘brand name’’ for a broader anti-TB package. Unless the current trend can be re- versed, says WHO, there will be 10.2 million new TB cases a year by 2005. And the goal of detecting 70% of cases through DOTS and curing 85% of them will not be reached until 2013— eight years later than the global target set at a ministerial conference held in Amsterdam in March 2000. And that’s not to mention multidrug-resistant TB, which is on the increase in many places, particularly in the former Soviet Union, where it has been encountered in up to 14% of new TB cases. The Global TB Drug Facility was launched in Washington DC on 21 March, with an initial US$ 10 million from the Canadian International Development Agency (CIDA). The first grants have now been approved to provide drugs to treat almost 200 000 patients in Africa, Asia, and Eastern Europe. Dr Jacob Kumaresan, executive secre- tary of theWHO-based Stop TB partnership, told the Bulletin: ‘‘The drugs used to treat TB have been available for over three decades, and the 6–8 month course of treatment for TB costs as little as US$ 10–15. But shortages of TB drugs are frequent and serious, often caused by financial constraints, inefficient drug procurement systems, and poor management. With the TB Drug Facility we will be able to ensure an uninterrupted supply of high-quality drugs, which should help to expand rapidly the use of DOTS.’’ Meanwhile, sympathisers of the anti-TB movement have taken advantage of World TB Day to give material expression to their support: the Bill and Melinda Gates Foun- dation announced a gift of US$ 10 million to the WHO-based tropical disease research programme (TDR) to fund the development of better diagnostic tests for TB, and the Dutch government offered 20million Dutch Guilders (about US$ 8 million) to the Stop TB partnership. n Sheila Davey, Geneva, Switzerland Winning drawing of WHO’s mental health contest This drawing is how Dhruva Suri, a 7-year-old boy from New Delhi, India, responded to WHO’s call for a picture of how a child with a brain disorder might experience his or her ‘‘difference’’. On 7 April, Suri was declared winner of WHO’s global school contest in the 6–9-year-old category by an international jury. More than 70 countries and thousands of children took part in the contest, which was organized as part of World Health Day (7 April) celebrations, devoted this year to mental health. The contest aimed, said Dr Benedetto Saraceno, head of WHO’s mental health programme, ‘‘to draw young people into the debate on how we can make good mental health a reality for everybody’’. An essay competition, on a mental health topic, was organized for older children. The winners were two girls, Tang Shu-wei, 14, of China, for the 10–14-year-old category, and Bibbie Kumangai, 17, of Palau, for the 15–18-year- old category. 487Bulletin of the World Health Organization, 2001, 79 (5) WHO News