What does cVDPV stand for?

• A. Centralized vaccine-derived poliovirus
• B. Circulating virus-derived poliovirus
• C. Circulating vaccine-derived poliovirus
• D. Continent-derived poliovirus

Answer: (C)

Circulating vaccine-derived poliovirus refers to poliovirus that originated from the oral polio vaccine and has begun spreading in a community. The key ideas are that the virus came from a vaccine strain (vaccine-derived) and that it is now circulating from person to person (circulating), not just found in one person or in a lab. When the live attenuated vaccine virus spreads in populations with low immunity, it can accumulate mutations and sometimes regain the ability to cause disease and transmit, leading to outbreaks. That combination—origin from the vaccine and sustained community transmission—defines this term. Other phrasing wouldn’t capture both the vaccine origin and the spread through a population.