Reducing the Risk of Unsafe Injections in Immunization Programmes: Financial and Operational Implications of Various Injection Technologies

Every year more than 550 million injections are administered in developing countries through the Expanded Program on Immunization. It is imperative that great care be given to providing these immunizations with only sterile injection equipment. Otherwise children may be subjected during immunization to infections such as hepatitis B virus and HIV. Sterilizable needles and syringes standard disposable needles and syringes autodestruct needles and syringes and jet injectors are currently available for administering vaccines. The design and operation of the former two types of needles and syringes are by definition evident. The design of autodestruct needles and syringes and jet injectors however is less directly apparent from their nomenclature. Autodestruct syringes have a device in the barrel which prevents the plunger from being redrawn after a single use thereby automatically blocking the syringe and preventing it from being reused. Jet injectors deliver immunizations with a high pressure jet of fluid generated by either a hydraulic or mechanical compression system. This equipment was developed for high workload use and has been employed in immunization campaigns for many years. Low workload injectors are being developed for use in the small immunization clinic setting. In general the cost per injection is lowest with sterilizable equipment and highest with the autodestruct device. Only autodestruct syringes however virtually eliminate the risk of unsafe injection practices. It must be emphasized that technology alone cannot eliminate the risk of accidental infection using unsterile injection equipment. The authors note that it may be appropriate in some settings to use a combination of equipment. For example autodestruct syringes may be used in areas where it is difficult to ensure adequate supervision while in medium-sized fixed-site clinics with safe injection practices sterilizable equipment will be the most cost-effective.