Q. Which of the following statements is true about Prophylactic medicines?

[A] It is the medication or a treatment designed and used to prevent a disease from occurring.

[B] It is the type of vaccine which combines a weak antigen with a strong antigen so that the immune system has a stronger response.

[C] It refers to the ingredients or active pharmaceutical substances which can eventually be converted into a medicine.

[D] It is the type of vaccine that uses a copy of a molecule called messenger RNA (mRNA) to produce an immune response.

Answer: A
Notes:
  • Statement a is correct: A prophylactic is a medication or a treatment designed and used to prevent a disease from occurring.  Example: A prophylactic hepatitis vaccine prevents the patient from getting hepatitis, while a prophylactic dental cleaning prevents tooth decay. 
  • Statement b is incorrect: It is the definition of Conjugate vaccines. 
  • Statement c is incorrect: It is the definition of API (Active Pharmaceutical Ingredients) vaccines. 
  • Statement d is incorrect: It is the definition of mRNA vaccines. 

Source: PIB