In a patient with a Salmonella infection, which of the following mechanisms will most likely be the earliest adaptive response for clearing the infection while bacteria are present within intracellular endosomes?

Ans. (d)DTH responses are generally the first effective responses involved in clearance of intraendosomal microbes. Later in such infections, the microbes or their molecules may escape into the cytoplasm, making it possible for Cytotoxic T lymphocyte responses to develop. Complement does not clear active intracellular infections. Antibodies maybe effective in inhibiting reinfection but do not cleat active intracellular infections.