Bihar CHO -2019: After how many hours should the remaining dose of measles vaccine not be used?

Bihar CHO -2019

Community Health Nursing

Easy

Appeared in: Bihar CHO -2019

Explanation

Measles vaccine is a live vaccine that must be reconstituted from a powder form before use.
Once reconstituted, it is extremely sensitive to heat and light and lacks preservatives, causing it to lose potency rapidly.
International and national immunization guidelines strictly mandate that any reconstituted measles vaccine must be discarded after 4 hours or at the end of the immunization session, whichever comes first.
This rule ensures the vaccine's effectiveness and prevents bacterial contamination, which could lead to severe adverse reactions like Toxic Shock Syndrome (TSS).

Option A: Using a reconstituted measles vaccine for 6 hours is incorrect and unsafe. The vaccine loses significant potency well before this time, rendering it ineffective.
Option C: An 8-hour window is far too long. The vaccine would be almost completely non-potent and could be contaminated, posing a risk to the recipient.
Option D: A 10-hour period is incorrect. This extended time would ensure the vaccine is completely ineffective and significantly increases the risk of severe adverse events due to contamination.

Clinical Relevance

Nursing practice connection: Safe nursing care depends on performing Handling and storage protocol for reconstituted measles vaccine in the correct sequence, documenting the action clearly, and monitoring for the expected response.
Adhering to the 4-hour rule is a critical nursing responsibility to ensure vaccine efficacy and maintain patient safety. Failure to do so can result in immunization failure, leaving a child unprotected against measles.
A crucial nursing action is to write the date and time of reconstitution on the vaccine vial immediately after mixing it. This prevents accidental use beyond the safe period.
This practice directly contributes to reducing vaccine wastage and preventing adverse events following immunization (AEFI).

How to Approach the Question

First, identify the core subject of the question: the measles vaccine.
Recall the specific properties of the measles vaccine. It is a live, attenuated vaccine that comes in a powder (lyophilized) form and needs to be reconstituted.
Remember that reconstituted vaccines have special, strict handling rules because they are preservative-free and lose potency quickly once mixed.
Differentiate this from the 'Open Vial Policy,' which applies to certain liquid, multi-dose vaccines (like DPT, TT) but explicitly excludes reconstituted vaccines like measles and BCG.
Based on this knowledge, recall the specific time limit for reconstituted vaccines.
Select the option that matches the standard guideline, which is 4 hours.

Concept Tested & Keywords

Concept Tested: Handling and storage protocol for reconstituted measles vaccine.
Stem keywords: measles vaccine, remaining dose, not be used, hours
Lead-in keywords: After how many hours
Negative lead-in flag: false

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E6 Parks TextBook of Preventive & Social Medicine part 1 — Subpart A (pp 26-201 of 604) p. 152-154

E6 Medicine Harrison 22e Part 1 p. 1683-1685