Which is not true about measles vaccine?
The core concept here is the properties and administration of the measles vaccine. Measles vaccine is a live attenuated vaccine, usually given as part of MMR (measles, mumps, rubella). It's important to know its contraindications, storage, administration route, and effectiveness.
Now, the correct answer is likely an option that states something incorrect. Let's think about common misconceptions. For example, if an option says it's given intravenously, that's wrong because it's subcutaneous or intramuscular. Also, contraindications like immunosuppression are important. If an option says it's safe during pregnancy, that's incorrect because MMR is contraindicated in pregnant women. Another point is that the vaccine is not effective if given after exposure; it must be given before. Also, the vaccine is stored in a refrigerator, not frozen.
Let me structure the explanation. The core concept is about the measles vaccine's characteristics. The correct answer would be a false statement. For example, if one of the options says it's a killed vaccine, that's wrong. Another incorrect point could be that it's given with a booster in early childhood. Wait, the standard is two doses: first at 12-15 months, second at 4-6 years. So if an option says only one dose is sufficient, that's incorrect. Also, the vaccine can't be given to immunocompromised individuals. So any option stating otherwise is wrong.
Now, for the incorrect options, each one should have a specific error. Let's assume the options are:
A. It is a live attenuated vaccine. (Correct)
B. Contraindicated in pregnancy. (Correct)
C. Stored in a refrigerator at 2-8°C. (Correct)
D. Provides lifelong immunity after one dose. (Incorrect)
So the correct answer would be D. The explanation would note that one dose is about 93% effective, but a second dose is recommended for lifelong immunity. So D is false because one dose doesn't provide lifelong immunity.
I need to make sure each section is covered. The core concept is the vaccine's type, administration, and effectiveness. The correct answer is the one stating it provides lifelong immunity after one dose. The wrong options would be the others, each explained why they're correct except the correct answer. Wait, no. The question is which is NOT true. So the correct answer is the false statement. So the correct answer in the explanation is the one that is false. For example, if the options are A-D, and D is the false one, then the correct answer is D. The explanation needs to clarify why the false statement is not true.
**Core Concept**
The measles vaccine is a **live attenuated vaccine** administered subcutaneously or intramuscularly. It is contraindicated in immunocompromised individuals and pregnant women due to its replication-competent nature.
**Why the Correct Answer is Right**
The statement "provides lifelong immunity after one dose" is false. While the measles vaccine is highly effective