Rabies virus is inactivated by –
**Core Concept**
The rabies virus is a lyssavirus that causes fatal encephalitis in mammals. Inactivation of the virus is crucial for the production of safe rabies vaccines. The process involves the use of chemicals or physical methods to render the virus non-infectious.
**Why the Correct Answer is Right**
The correct answer is **formaldehyde**. Formaldehyde is a potent disinfectant and virucide that inactivates the rabies virus by cross-linking proteins and disrupting viral structure. This process is essential for the production of inactivated rabies vaccines, which are used to prevent the disease. Formaldehyde is added to the vaccine to inactivate the virus, making it safe for human use.
**Why Each Wrong Option is Incorrect**
**Option A:** Autoclaving is a method of sterilization that uses high-pressure steam to kill microorganisms. While autoclaving can inactivate some viruses, it is not the primary method used to inactivate the rabies virus.
**Option B:** Ultraviolet light (UV) is a form of electromagnetic radiation that can inactivate microorganisms. However, UV light is not effective against the rabies virus, which requires a more potent disinfectant like formaldehyde.
**Option C:** Beta-propiolactone is a chemical used as a disinfectant and virucide, but it is not the primary method used to inactivate the rabies virus.
**Clinical Pearl / High-Yield Fact**
Rabies vaccines are typically produced using a combination of formaldehyde inactivation and filtration to remove any remaining viral particles. This process ensures the safety of the vaccine and prevents the transmission of the disease.
**Correct Answer: D. Formaldehyde.**