Most common cause of secondary immunodeficiency?

Correct Answer: A

Rationale: Protein malnutrition is the most common cause of secondary immunodeficiency globally, as it impairs the production of immune cells and antibodies.

Correct Answer: C

Rationale: The hepatitis A vaccine is an inactivated (killed) virus vaccine, providing immunity without risk of infection.

Correct Answer: D

Rationale: IL-4 from Th2 cells drives B cells to produce IgE, a key factor in atopy and allergic responses.

Correct Answer: C

Rationale: Chronic granulomatous disease (CGD) is indicated by recurrent infections with catalase-positive organisms like Staphylococcus aureus, including lymphadenitis and liver abscesses, due to defective phagocyte function. Bruton agammaglobulinemia involves B-cell defects, AIDS is a T-cell disorder, and Kostmann disease is severe congenital neutropenia, none of which fit this presentation as well as CGD.

Correct Answer: A

Rationale: DiGeorge syndrome is caused by a 22q11.2 deletion (often written as 22q12 in shorthand), affecting thymic development. No other listed condition matches this chromosomal defect.