Which of the following is NOT a mode of transmission for diseases?

Immunization is a method of protecting individuals from diseases rather than a mode of transmission. It works by introducing a vaccine to stimulate the body's immune response, helping to prevent infection from specific pathogens.

In contrast, direct transmission, contamination, and bloodborne transmission are all ways in which diseases can be spread. Direct transmission refers to the immediate transfer of pathogens from one person to another, often through physical contact. Contamination involves the presence of infectious agents on surfaces or objects that can be transferred to individuals. Bloodborne transmission specifically occurs when pathogens are transmitted through blood, often through transfusions or sharing needles.

Thus, choosing immunization highlights an important distinction in the context of disease prevention versus transmission methods.