by Yves Chartier, WHO, and Olga Popova, Crucell Worldwide immunization programs have had an enormously positive impact on health and health care since 1974 when the World Health Assembly launched the Expanded Programme on Immunization. However, like all great achievements the effort has unveiled new challenges. One of the most serious has been the re-use of syringes without adequate sterilization. As this issue came to light in the 1950s, disposable syringes were developed to resolve the problem. Unfortunately, they did not, and the rise of HIV/AIDS and hepatitis B and C transmission raised the issue into an even greater sphere of concern. The late 1980s brought the successful development and deployment of autodisable syringes, which are now in widespread use in immunization programs. And while autodisable syringes have considerably reduced re-use and contamination issues—at least within the relatively narrow confines of immunization programs—their use has given rise to an associated concern, how to manage injection-related waste. Improper management of injection-related waste can have both direct and indirect health consequences for health personnel, community members, and the environment. Direct consequences of improper waste management arise when disposable materials (especially syringes) are intentionally re-used. The transmission of hepatitis B and C and HIV represent the main disease burden caused by inadequate management of injection-related waste. Unintentional injuries may also occur when people mishandle or are exposed to inadequately disposed waste, for example through scavenging on waste sites. Indirect health effects can arise from environmental pollution in the form of toxic emissions from inadequate burning of medical waste or in the sheer volume of waste generated in a short period of time. For instance, a countrywide mass immunization campaign will produce millions of used syringes in a period of three to four weeks. This requires appropriate options and a well-prepared strategy defined months before the campaign starts. A variety of technologies have been developed to aid in the safe storage, collection, treatment, and disposal of health care wastes. Several types of treatment and disposal processes, such as incineration, microwave or chemical treatment, and melting have been applied in health care settings with varying degrees of safety, cost, and impact on the environment. However most are geared toward industrialized country settings. None of the available low-cost treatment devices (i.e., below US$500) on the market are both safe and environmentally friendly. In developing countries, a trade-off has to be made between direct health risks resulting from the absence of a waste management strategy, and indirect health risks created by environmental pollution (e.g., by production of dioxins from inadequate incineration). Despite the difficult tradeoffs in waste management approaches, countries are better off with a waste management strategy than without one. Some countries have made significant improvements by adopting purchase policies that consider the waste stream and/or by isolating and treating the most harmful segments of the waste. At the global level, vaccine manufacturers and injection equipment suppliers are also seeking solutions. Crucell, for example, is adopting a holistic approach to its pentavalent vaccine, looking for solutions that can meet the needs of complex, developing-country environments. First, it changed its formulation from lyophilized to liquid, thus reducing opportunities for reconstitution errors, eliminating multiple procedural steps, shortening the vaccination session, shrinking storage needs, and minimizing waste. Next, it offered the vaccine in single-dose vials, thus reducing vaccine wastage, eliminating the need for preservatives, and minimizing the possibility of contamination. Recently it has begun to explore the feasibility of offering liquid pentavalent vaccine in the UnijectTM injection system, a plastic, compact prefilled autodisable system. Belying its big name, Uniject is nothing more than a small bubble of plastic attached to a needle. It is precisely prefilled with a single dose by manufacturers, thus eliminating vaccine wastage or improper dosing. It is so easy to use that health workers need a scant two hours of training before successfully using it. From a waste-management perspective, Uniject cannot be reused, thus minimizing the threat of disease transmission. It contains only about 35 percent of the plastic of a standard disposable syringe, and the type of plastic used in Uniject can be incinerated without generating toxic fumes (unlike those produced by with a rubber piston). By testing and seeking solutions such as these, pharmaceutical companies like Crucell can ameliorate some of the health care waste management problem countries face. Ultimately, the waste management conundrum must be addressed at all levels, from upstream technology development to downstream waste minimization and management, to ensure that health care can be delivered without side effects on health care workers, communities, or the environment. To comment, click reply.