Question

Children are vaccinated in the polio eradication programme, because

• A. Vaccination kills the polio causing micro-organisms.
• B. It prevents the entry of polio causing organisms.
• C. It develops immunity in the body.
• D. All of the above.

Answer 1

The correct option is C It develops immunity in the body.

The oral polio vaccine contains a live, attenuated (weakened) vaccine-virus. When a child is vaccinated, the weakened vaccine-virus replicates in the intestine and enters into the bloodstream, triggering a protective immune response in the child. Like wild poliovirus, the child excretes the vaccine-virus for a period of six to eight weeks. Importantly, as it is excreted, some of the vaccine-virus may no longer be the same as the original vaccine-virus as it has genetically altered during replication. This is called a vaccine-derived poliovirus.

Therefore, the correct answer is option C.