**Question:** All of the following rabies vaccines are commercially available except -

A. Rabipur
B. Imovax
C. Rabisimplex
D. Rabisorb

**Core Concept:** Rabies is a viral infection caused by the rabies virus, which affects the central nervous system. Vaccines play a crucial role in preventing rabies infection. There are various rabies vaccines available, and understanding their differences is essential for healthcare professionals.

**Why the Correct Answer is Right:** Only one option is not commercially available among the provided choices. Rabisorb is not mentioned as a rabies vaccine option. Rabisorb is actually an adjuvant used in some vaccines, not a standalone rabies vaccine.

**Why Each Wrong Option is Incorrect:**

A. Rabipur: Rabipur is a well-known rabies vaccine produced by Serum Institute of India. It is a well-established vaccine that has been used globally for preventing rabies infection.

B. Imovax: Imovax is another widely used rabies vaccine produced by Euroimmun. It is a valid option for preventing rabies infection.

C. Rabisimplex: Rabisimplex is a rabies vaccine produced by Mérieux NutriSciences. It is a valid option for preventing rabies infection.

D. Rabisorb: As mentioned earlier, Rabisorb is an adjuvant used in some vaccines but not a standalone rabies vaccine.

**Clinical Pearl:**

Understanding the correct vaccines available for preventing rabies infection is essential for healthcare professionals. Some vaccines have adjuvants like Rabisorb, which is used to enhance the immune response to the vaccine, but Rabisorb itself is not a rabies vaccine. It is crucial to differentiate between adjuvants and vaccines when recommending appropriate preventive measures for rabies exposure.

**Correct Answer:** D. Rabisorb (not a rabies vaccine)

**Explanation:**

Rabies vaccines are essential tools in preventing rabies infection. The vaccines mentioned are: Rabipur, Imovax, and Rabisimplex. Rabipur, Imovax, and Rabisimplex are all valid options for preventing rabies infection as they are licensed and widely used vaccines. Rabisorb, on the other hand, is an adjuvant used in some vaccines to enhance the immune response, but it is not a rabies vaccine itself. Hence, option D (Rabisorb) is the correct answer as it is not a rabies vaccine. Understanding the distinction between adjuvants and vaccines is crucial for healthcare professionals when recommending preventive measures for rabies exposure.