Question

Assertion (A): The 23 valent pneumococcal vaccine is not recommended for routine use in children.

Reason (R): Most pneumococcal strains are still susceptible to penicillin.

• A. Both A and R are true and R is the correct explanation of A.
• B. Both A and R are true but R is NOT the correct explanation of A.
• C. A is true but R is false.
• D. A is false but R is true.

Hint:

Think about why polysaccharide vaccines work poorly in infants, and about rising penicillin resistance in pneumococcus.

Answer 1

The Correct Option is C

This question separates two different claims: one about vaccine policy for children, and one about antibiotic resistance in pneumococcus.

1. Assertion: The 23-valent pneumococcal vaccine is a pure polysaccharide vaccine, and young children cannot build a strong antibody response to plain polysaccharide antigens. That is why it is kept out of routine childhood use and a conjugate vaccine is used instead for infants. So the assertion is true.
2. Reason: Saying most pneumococcal strains are still penicillin-susceptible ignores the well documented rise of penicillin-resistant and reduced-susceptibility strains that had already become a major concern by this period, in India and worldwide. So the reason is not correct.

Because the reason is false, it cannot explain the assertion, even though the assertion itself stands true for a completely different reason involving immune maturity in young children.

Let's summarize:

• Polysaccharide vaccines like PPSV23 are weak immunogens before age two.
• Conjugate vaccines solve this by attaching a protein carrier.
• Penicillin resistance in pneumococcus was rising, not staying low, which is why the reason fails.

So the final answer is: A is true but R is false.