All are true about polio vaccines except
**Core Concept**
The polio vaccines, including Oral Poliovirus Vaccine (OPV) and Inactivated Poliovirus Vaccine (IPV), are crucial in the global effort to eradicate poliomyelitis. Understanding the characteristics of each vaccine is essential for public health policy and individual patient care.
**Why the Correct Answer is Right**
IPV (Inactivated Poliovirus Vaccine) is a killed-virus vaccine, meaning that the virus is inactivated with a chemical or physical method, making it incapable of causing disease. This contrasts with OPV (Oral Poliovirus Vaccine), which is a live attenuated vaccine, containing weakened forms of the poliovirus that can still cause a mild infection. IPV does not provide intestinal immunity, as it is administered intramuscularly and does not replicate in the gut. Intestinal immunity is primarily provided by OPV, which replicates in the gut and stimulates a mucosal immune response.
**Why Each Wrong Option is Incorrect**
**Option A:** OPV is indeed a live attenuated vaccine, which is a deliberate weakening of the virus to prevent it from causing severe disease while still inducing an immune response.
**Option C:** IPV is indeed a killed-virus vaccine, which is inactivated with a chemical or physical method to prevent it from causing disease.
**Option D:** OPV is effective during epidemics, as it provides intestinal immunity and can help to interrupt the transmission of poliovirus within a community.
**Clinical Pearl / High-Yield Fact**
It's essential to note that IPV and OPV have different administration schedules, with IPV typically given in a series of injections and OPV given orally. Additionally, OPV has the added benefit of providing mucosal immunity, which is critical for preventing poliovirus transmission.
β Correct Answer: B. IPV Provides Intestinal immunity