Which of the following would NOT be considered a vector for infection?

In the context of infection and disease transmission, a vector is an organism that does not cause disease itself but transmits pathogens from one host to another. Both mosquitoes and ticks are classic examples of biological vectors; they harbor pathogens and transmit them during feeding. Humans can also act as vectors, either by carrying pathogens without exhibiting symptoms or by serving as hosts that can spread diseases to others.

A wall surface, however, does not qualify as a vector. It can be a surface that carries microorganisms but does not actively participate in the transmission of pathogens in the way that living organisms do. Instead, it can facilitate transmission through indirect contact, such as when a person touches the surface and then their face, but it lacks the ability to carry pathogens from one host to another. Therefore, it does not fit the definition of a vector for infection.