Principles of Immunization and Vaccination MCQs

Answer- A. 1 goal is to start within one to two hours or earlier after exposure often using a starter pack with appropriate drugs as immediately available. The median time to initiation of postexposure prophylaxis is 1.8 hrs. The centre for disease control and prevention (CDC) recommendations are to offer prophylaxis upto 24-36 hrs after exposure, for longer time lapses, the recommendations is to seek advice from an expert

Explanation: Pentavalent vaccine (which protects against Diphtheria, Pertussis, Tetanus, Hepatitis B, and Hib) is a liquid vaccine that comes in multi-dose vials and does follow the open vial policy . If stored correctly (2-8°C), not expired, unopened vials are clean, and aseptic technique is followed, it can be used up to 28 days after opening. Explanation for other options: BCG (option A): Does not follow open vial policy. It is a lyophilized (freeze-dried) vaccine that must be reconstituted and used within 4-6 hours. After that, it must be discarded. JE (option C): incorrect it is also a lyophilized vaccine, and once reconstituted, it must be used within a short time (usually 4 hours). Does not follow open vial policy. MMR (option D): incorrect it is also lyophilized, and must be used within 4 hours of reconstitution. Does not follow open vial policy.