Reconstitute measles vaccine can be kept at 2° C to 8° C for maximum of-

RUHS, Jaipur, PB B.Sc Nursing Entrance-2022

Pharmacology

Easy

Appeared in: RUHS, Jaipur, PB B.Sc Nursing Entrance-2022

Explanation

Measles vaccine is a live attenuated vaccine that is reconstituted from a powder form before administration.
Once reconstituted, the vaccine is highly unstable and rapidly loses potency. It also lacks preservatives, creating a risk for bacterial growth.
To prevent bacterial contamination (especially from Staphylococcus aureus, which can cause Toxic Shock Syndrome) and ensure efficacy, the vaccine must be used within a maximum of 4 hours.
The vaccine must be stored at 2°C to 8°C and protected from light during this 4-hour window.
Any vaccine remaining after 4 hours or at the end of the immunization session, whichever is earlier, must be discarded.

Option A: While using the vaccine as soon as possible is recommended, the established safe maximum window is 4 hours. Discarding it at 2 hours is not necessary and could lead to vaccine wastage.
Option C: Using the vaccine for up to 6 hours significantly increases the risk of bacterial contamination and the development of Toxic Shock Syndrome (TSS). While some international guidelines may mention 6 hours, the stricter 4-hour rule is often followed for enhanced safety, especially in Indian public health guidelines.
Option D: This is far beyond the safe usage period. A vaccine used after 8 hours would have questionable potency and pose a severe risk of causing a serious infection due to bacterial contamination.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Vaccine storage and handling protocols for live attenuated vaccines as background academic context rather than a clinical decision trigger.
Adherence to the 4-hour rule is a critical nursing responsibility to prevent patient harm from Toxic Shock Syndrome (TSS), a life-threatening complication.
Properly labeling the vial with the time of reconstitution is a simple but vital nursing action that ensures patient safety during mass immunization campaigns.
What if? If an immunization session ends 2 hours after the measles vaccine was reconstituted, the remaining vaccine must still be discarded. The rule is to discard after 4 hours OR at the end of the session, whichever comes first.

How to Approach the Question

First, identify the keywords in the question: 'Reconstitute measles vaccine', 'maximum' time, and the temperature '2° C to 8° C'.
Recall the properties of live attenuated vaccines like measles. They are sensitive and lose potency after being mixed with a diluent.
The most critical concept to remember for reconstituted measles vaccine is the risk of bacterial contamination and Toxic Shock Syndrome (TSS), which dictates a strict time limit for safety.
Evaluate the options based on this safety principle. The 4-hour rule is a standard, widely taught safety guideline in nursing.
Eliminate shorter options (like 2 hours) as potentially wasteful if a longer safe window exists, and eliminate longer options (6 or 8 hours) as they pose an unacceptable risk of contamination and potency loss.

Concept Tested & Keywords

Concept Tested: Vaccine storage and handling protocols for live attenuated vaccines.
Stem keywords: Reconstitute measles vaccine, 2° C to 8° C, maximum
Lead-in keywords: maximum of

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