Vaccination induces active immunity against whooping cough

Steps:

• Whooping cough is caused by Bordetella pertussis bacteria, requiring preventive immunity for infants.
• Antibiotics treat existing infections but do not build long-term protection.
• Passive immunity from antibodies offers short-term defense without memory cell formation.
• Active immunity from antigens triggers the body's own antibody production and lasting protection.

Why D is correct:

• Injections of antigens from Bordetella pertussis act as a vaccine, stimulating the immune system to produce specific antibodies and memory cells for lifelong immunity, per immunological principles of vaccination.

Why the others are wrong:

• A: Short antibiotic course treats symptoms but provides no preventive or lasting immunity.
• B: Six-month antibiotic course manages infection but does not induce immune memory.
• C: Antibody injections deliver passive, temporary protection that wanes without reducing future disease risk.

Final answer: D