What are the general qualities of IPV and OPV?

• A. Both require injection
• B. IPV is live-attenuated and oral; OPV is inactivated and injection.
• C. IPV is inactivated and requires injection; OPV is live-attenuated and administered orally.
• D. Both are oral vaccines

Answer: (C)

The main idea is how IPV and OPV are made and given. IPV uses an inactivated (killed) polio virus and is administered by injection, while OPV uses a live-attenuated virus and is given orally. This distinction matters for the kind of immunity each vaccine promotes and for safety considerations: IPV provides strong systemic immunity and cannot cause polio, but it doesn’t stimulate gut mucosal immunity as effectively as OPV; OPV induces mucosal immunity in the gut and is easier to administer, but it carries a tiny risk of vaccine-derived poliovirus or vaccine-associated paralytic poliomyelitis because it contains a live virus. The other statements misstate either the virus type or the route of administration (for example, saying both require injections, or both are oral, or swapping inactivated versus live-attenuated).