MCQ – 97610

Correct Answer » B Explanation

Detailed Explanation:

Clinical Reasoning for the Correct Answer:
– The Open Vial Policy allows for reuse of certain vaccines’ multidose vials across sessions if proper aseptic technique is maintained.
– Vaccines containing preservatives (e.g., DPT, TT, hepatitis B, OPV) can be reused if kept under recommended conditions.
– Lyophilized (freeze-dried) vaccines, such as BCG and measles, do NOT contain preservatives and must be used within a few hours of reconstitution.

Why Option A (BCG vaccine) is Incorrect:
– BCG is a live-attenuated, lyophilized vaccine.
– Once reconstituted, it must be discarded within 6 hours or at the end of the immunization session.
– No preservatives present to prevent contamination after reconstitution.
– Other vaccines in this category: Measles, MR, JE lyophilized.

Why Option B (DPT vaccine) is Correct:
– DPT is a liquid vaccine containing preservatives.
– Multidose vials can be used across immunization sessions for up to 28 days, provided sterile technique and proper cold chain are maintained.
– Applies also to Hepatitis B, Oral Polio Vaccine, TT (Tetanus Toxoid).

Why Option C (Measles vaccine) is Incorrect:
– Measles vaccine is also live-attenuated and lyophilized.
– Discard within 4–6 hours after reconstitution or at session end.
– Lacks preservatives; risk of bacterial contamination if kept longer.

Why Option D (Both A & C) is Incorrect:
– Both BCG and Measles must be discarded after use within one session.
– Neither is eligible for multi-session use under Open Vial Policy.

High‑Yield Synopsis:

Open Vial Policy (WHO/UNICEF):
– Vaccines Eligible for Multi-session Use
– Liquid formulations with preservatives: DPT, DT, TT, Hepatitis B, Oral Polio Vaccine (OPV).
– May use up to 28 days post-opening with proper storage and technique.
– Vaccines Ineligible (Single Session Only)
– Lyophilized vaccines (no preservative): BCG, Measles, MR, JE (after reconstitution).
– Must discard within 4–6 hours of opening or at session end.
– Rationale
– Preservative-containing formulations prevent microbial growth.
– Reconstituted/lyophilized vaccines lack preservatives; high contamination risk.
– Handling Requirements
– Maintain cold chain (2–8°C).
– Label vials with date of opening.
– Discard if sterility breached, expiry reached, appearance changed, or label unreadable.

Differential Points:
– DPT/TT/HepB/OPV: Liquid + preservative → multi-session use.
– BCG/Measles/MR/JE (reconstituted): Lyophilized, no preservative → single session only.