When preparing vaccines for administration, each injection should be prepared:

Preparing vaccines right before administration is crucial in ensuring their effectiveness and safety. Vaccines often contain live attenuated viruses, proteins, or other antigens that can degrade or lose their potency if they are not handled properly. Preparing vaccines immediately before they are needed minimizes the risk of contamination and ensures that they are kept at the correct temperature, as many vaccines have strict storage requirements.

Additionally, preparing vaccines shortly before administration allows for proper reconstitution when needed, which is important for vaccines provided in a powdered form that require a diluent. This process ensures that the vaccines maintain their efficacy and are within the stability window established by manufacturer guidelines.

Preparing vaccines in bulk in advance might lead to potential waste if they are not used in time or if there is a risk of spoilage. Multi-dose vials should be used only when appropriate and with strict aseptic techniques to prevent contamination, and it is essential to use the correct diluent as specified by the vaccine manufacturer to ensure proper consistency and effectiveness.