Which of the following vaccines is recommended for infants at 2 months of age to protect against whooping cough (pertussis)?

Explanation: Sjögren's syndrome is an autoimmune disorder in which the immune system attacks and damages the salivary and lacrimal glands, resulting in dry eyes and dry mouth.

Incorrect choices:

a. Rheumatoid arthritis primarily affects the joints, causing inflammation and joint damage.

c. Crohn's disease is an autoimmune disorder that affects the gastrointestinal tract, leading to inflammation and ulcers.

d. Psoriasis is a chronic skin condition characterized by red, scaly patches on the skin, and it is not related to the salivary and lacrimal glands.

Explanation: During cell-mediated immunity, T cells recognize antigens that are presented by antigen-presenting cells (APCs) such as macrophages. Macrophages engulf and process pathogens, and then they display fragments of the pathogens' antigens on their cell surface using major histocompatibility complex (MHC) molecules. T cells, specifically helper T cells, interact with these antigen-presenting macrophages and become activated to initiate immune responses.

Incorrect choices:
b. B cells present antigens to helper T cells during the humoral immune response, not during cell-mediated immunity.
c. Plasma cells are not involved in antigen presentation; they are terminally differentiated B cells that produce antibodies during the humoral immune response.
d. Memory cells are formed after the immune system encounters an antigen and are not directly involved in antigen presentation.