True regarding SA-14-14-2 Japanese Encephalitis vaccine:
**Core Concept**
The SA-14-14-2 Japanese Encephalitis (JE) vaccine is a live attenuated vaccine designed to protect against JE virus infection, a significant cause of viral encephalitis in Asia. The vaccine works by inducing immune responses against the JE virus, thereby preventing the disease.
**Why the Correct Answer is Right**
The SA-14-14-2 JE vaccine is a live, attenuated vaccine that is administered in a two-dose regimen, typically given 28 days apart. The vaccine is highly effective in preventing JE virus infection, with efficacy rates ranging from 90% to 100%. The vaccine induces both humoral and cellular immune responses, providing long-term protection against the JE virus.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as the SA-14-14-2 JE vaccine is a live, attenuated vaccine, not a killed-virus vaccine.
**Option B:** This option is incorrect as the SA-14-14-2 JE vaccine is not a conjugate vaccine, which combines a polysaccharide antigen with a carrier protein to enhance immunogenicity.
**Option C:** This option is incorrect as the SA-14-14-2 JE vaccine is not a recombinant vaccine, which uses genetic engineering to produce a vaccine.
**Clinical Pearl / High-Yield Fact**
The SA-14-14-2 JE vaccine is a critical tool in preventing JE virus infection in endemic areas, particularly in rural regions where the disease is most common. It is recommended that individuals traveling to JE-endemic areas receive the vaccine to protect against this potentially life-threatening disease.
**Correct Answer: D**