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:

Ask whether the reason talks about vaccines or about antibiotics.

Answer 1

The Correct Option is B

This question is really about spotting whether a true reason is actually connected to the assertion, or just true on its own. Let's check each option.

1. Both true, R explains A: This does not fit, because penicillin sensitivity of the bacteria has nothing to do with how well a child's immune system reacts to a polysaccharide vaccine.
2. Both true, R does not explain A: The 23 valent vaccine is made of plain polysaccharide, and young children under two years cannot mount a strong, lasting antibody response to such antigens, so it is skipped for routine use at that age and given instead to older, high risk children. Separately, it is true that many pneumococcal strains still respond to penicillin, but that fact is about treating infection with antibiotics, not about vaccine immunogenicity. The two ideas run on separate tracks, so this option fits.
3. A true, R false: This fails since the statement about penicillin susceptibility is not false, just unrelated.
4. A false, R true: This fails since the assertion about limited routine use in children is correct.

The key distinction is that vaccine recommendations turn on immune response by age, while antibiotic choice turns on drug resistance patterns. Mixing the two gives a true looking but wrong explanation.

Let's summarize:

• PPSV23 is skipped for routine use under two years because of weak antibody response to polysaccharide antigens.
• Penicillin susceptibility of the bacteria is a real but unconnected fact about treatment, not vaccination.

So both statements are true, but the reason does not explain the assertion.