If a vaccine requires reconstitution, what should be used?

• A. Tap water
• B. The rehydrating solution packaged with the vaccine
• C. Salt water from a pharmacy
• D. Alcohol

Answer: (B)

Reconstituting a vaccine requires using the specific diluent provided by the manufacturer. This sterile diluent is formulated to be compatible with the vaccine’s components, preserving its potency, stability, and safety. Using anything else can introduce contaminants, alter the concentration or pH, and potentially reduce effectiveness or cause reactions.

Tap water is unsafe for injections because it isn’t sterile and can bring microbes and impurities. Salt water from a pharmacy isn’t guaranteed to be the exact diluent and tonicity required for that vaccine, so it could change the final dose or how the vaccine behaves. Alcohol isn’t suitable either; it can irritate tissue and may damage vaccine proteins. Therefore, the correct choice is the rehydrating solution packaged with the vaccine.