Vaccine-associated paralytic poliomyelitis (VAPP) is best described as?

• A. It is a rare complication associated with OPV
• B. It occurs with IPV
• C. It occurs only after natural infection
• D. It is a common outcome of vaccination

Answer: (A)

Vaccine-associated paralytic poliomyelitis is a rare adverse event caused by the live, attenuated poliovirus in the oral polio vaccine. In rare cases, this vaccine virus can mutate back to a neurovirulent form and paralyze the vaccine recipient or a close contact who has been exposed. Because it involves a live virus, this complication does not occur with the inactivated polio vaccine, which uses killed virus and cannot revert to a paralytic form. It is not a consequence of natural infection and is not a common outcome of vaccination. So, the best description is that VAPP is a rare complication associated with OPV.