Paper II
Question
Vaccines used to prevent poliomyelitis with immunization schedule.
Answer
Vaccines used to prevent poliomyelitis:
- Oral Polio Vaccine (OPV) — live attenuated, trivalent (now bivalent, following wild poliovirus type 2 eradication); induces both systemic and local intestinal mucosal (secretory IgA) immunity.
- Inactivated Polio Vaccine (IPV) — killed vaccine, given by injection; induces systemic immunity without any risk of vaccine-associated paralytic poliomyelitis.
Immunization schedule: OPV given at birth (0 dose), and as part of the primary series at 6, 10, and 14 weeks of age, per most national schedules (e.g., India’s Universal Immunization Programme); IPV is co-administered (e.g., at 6 and 14 weeks, or per national schedule) in many current programmes alongside OPV; booster doses are given later in childhood (e.g., at 16–24 months). Supplementary Immunization Activities (SIAs, “Pulse Polio” rounds) provide additional OPV doses to all children under 5 during mass campaigns in endemic/high-risk countries, regardless of prior vaccination status.