4.1.2  Preparing injection equipment

Syringe selection

A separate syringe should be used for each injection. BCG vaccine should be injected using a 0.1 ml syringe; for all other EPI vaccines, use a 1 ml syringe. Disposable syringes are supplied in sterile plastic packages and are designed to be used once only and then put into a safety box. The safest type recommended by the World Health Organization is the auto-disable (AD) syringe (Figure 4.3). This has the needle already attached and a plunger mechanism that prevents the syringe from being used a second time. If the syringe and needle are supplied separately, when you remove a syringe from its package, take care not to touch the syringe adapter shown in Figure 4.4.

Figure 4.3  Auto-disable 1 ml syringes, supplied with needles already attached. (Photo: Basiro Davey)

Needle selection

The needle used should be of the appropriate diameter for the vaccine. Typically, vaccines are not very thick liquids, and therefore a fine needle size of 22–26 gauge (outer diameter) can be used. A new needle and syringe is used for each injection. Note that for vaccines that need to be reconstituted with diluent before use, you should use a separate ‘mixing’ syringe and needle (like those shown in Figure 4.4) for reconstitution. Use a new auto-disable (AD) syringe and needle to inject the client.

Figure 4.4  Parts of a syringe and a hollow needle, showing the areas that should not be touched. (Source: Adapted from WHO, 2004, Immunization in Practice, Module 4, Ensuring Safe Injections, Figures 4-B and 4-C)

Figure 4.4 shows the parts of a needle — none of which should be touched. Open the protective wrapping around the needle and remove it without touching the adaptor. The needle is inside a plastic outer case. Holding the needle by the outer case, push the needle adapter onto the syringe adapter until they ‘lock’ together firmly.

Vaccine reconstitution is taught in the next section. Diluents were introduced in Study Session 2.