Which of the following is a step in properly drawing up a vaccine?

Drawing up air equal to the volume of the vaccine is a critical step in the process of properly preparing a vaccine for administration. This practice is especially important when working with multi-dose vials or any vaccine that requires the drawing up of fluid from a container. By injecting air into the vial equal to the volume of the vaccine to be drawn, you help equalize the pressure inside the vial, which facilitates the smooth withdrawal of the vaccine solution. This helps prevent the formation of a vacuum within the vial that could make it difficult to draw up the correct amount of vaccine.

While mixing the vaccine with the diluent is an important aspect of preparing certain vaccines, it is not a universal step for all vaccines. Similarly, checking the patient’s age, although relevant for determining vaccine eligibility and dosage, does not pertain directly to the preparation of the vaccine itself. Injecting more air than the volume to be drawn is counterproductive and could lead to improper vaccine administration. Hence, the correct approach is to draw up air equal to the volume of the vaccine, ensuring an efficient and accurate preparation process.