What are the key concepts to focus on for an exam on the 8-point agenda, specifically regarding immunization routes, dosages, and community health nursing topics, including the differences between Inactivated Poliovirus Vaccine (IPV) and Oral Poliovirus Vaccine (OPV)?

Immunization Exam Preparation: Key Concepts for Community Health Nursing

IPV vs OPV: Critical Differences

The fundamental distinction is that IPV (Inactivated Poliovirus Vaccine) is administered intramuscularly or subcutaneously and carries zero risk of vaccine-associated paralytic poliomyelitis (VAPP), while OPV (Oral Poliovirus Vaccine) is given orally and carries a small but definite risk of paralysis, particularly after the first dose. 1, 2

Route of Administration

• IPV: Intramuscular (IM) or subcutaneous (SC) injection 3

  • In infants and small children: mid-lateral aspect of the thigh 3
  • In older children and adults: deltoid area 3
  • Never administer intravenously 3

• OPV: Oral administration 1

  • If infant regurgitates or spits out vaccine within 5-10 minutes, another dose can be administered at the same visit 1
  • If repeat dose not retained, neither dose should be counted 1

Immunological Differences

• IPV: Induces strong humoral (serum antibody) immunity but limited mucosal immunity 4, 5

  • Protects against paralytic disease 5
  • Reduces but does not completely prevent intestinal infection 4, 5

• OPV: Induces both humoral and superior mucosal (intestinal) immunity 1

  • Better at preventing intestinal infection and viral spread 1
  • Provides indirect protection to unvaccinated contacts through viral shedding 1

Safety Profile

• IPV: No risk of VAPP; well-tolerated with no serious adverse events 6, 7

  • Contraindicated only in persons with hypersensitivity to vaccine components (2-phenoxyethanol, formaldehyde, neomycin, streptomycin, polymyxin B) 6, 3

• OPV: Risk of VAPP is 1 case per 750,000 doses for first dose and 1 per 2.4 million doses overall 8

  • Should not be administered to immunocompromised persons 1
  • Between 1980-1996,134 of 142 paralytic polio cases in the US were VAPP 8

Standard Immunization Schedules

Children - IPV Schedule (Current US Recommendation)

All children should receive four doses of IPV at ages 2,4,6-18 months, and 4-6 years. 9, 6

• Minimum intervals between doses: 6

  • 4 weeks between doses 1 and 2
  • 4 weeks between doses 2 and 3
  • 6 months between doses 3 and 4

• Final dose must be administered at age ≥4 years regardless of number of previous doses 6

• Dosage: 0.5 mL per dose 3

• No need to restart series regardless of time elapsed between doses 9, 6

Historical OPV Schedules

• First dose typically given at 6 weeks of age with DTP 1
• In polio-endemic countries, extra dose often given at birth or ≤2 weeks of age 1
• Primary series: three doses separated by minimum 6 weeks (42 days) 1

Mixed IPV/OPV Series

• If both OPV and enhanced-potency IPV received: primary series consists of combined total of three doses 1, 10
• If OPV and conventional IPV received: primary series requires four total doses 1
• Any dose administered at recommended minimum intervals is valid 1

Adults - Unvaccinated

Primary series for unvaccinated adults consists of three 0.5 mL doses of IPV. 1, 6

• Standard schedule: 6, 3

  • First two doses: 4-8 weeks apart
  • Third dose: 6-12 months after second dose

• Accelerated schedules when time is limited: 3

  • If <3 months but >2 months available: three doses at least 1 month apart
  • If only 1-2 months available: two doses at least 1 month apart
  • If <1 month available: single dose

Adults - Previously Vaccinated

• Completely vaccinated adults at increased risk: one 0.5 mL booster dose of IPV 3
• Incompletely vaccinated adults: at least one dose of IPV; additional doses to complete primary series if time permits 3

Indications for Adult Vaccination

IPV is recommended for adults at increased risk of poliovirus exposure, including: 1, 6

• Travelers to areas where polio is epidemic or endemic 6
• Laboratory workers handling specimens that might contain polioviruses 1, 6
• Healthcare workers with close contact with patients who might be excreting polioviruses 1, 6
• Members of communities with disease caused by wild polioviruses 6

Vaccine Administration Principles

General Standards

• Never vary from recommended route, site, volume, or number of doses 1

• Administering vaccines by wrong route can result in: 1

  • Inadequate protection (e.g., hepatitis B in gluteal vs. deltoid)
  • Increased risk for reactions (e.g., DTP subcutaneous vs. intramuscular)

• Split doses or reduced doses are not endorsed 1

  • Any vaccination using less than standard dose or nonstandard route should not be counted 1
  • Person should be revaccinated according to age 1

Injection Technique for IPV

• Inspect vial for particulate matter, discoloration, leakage, or faulty seal before use 3
• Do not remove vial stopper or metal seal 3
• Use aseptic technique with sterile needle 3
• Avoid administering into or near blood vessels and nerves 3
• If blood or suspicious discoloration appears in syringe, discard and repeat with new dose at different site 3

Contraindications and Precautions

• IPV contraindications: 6

  • History of hypersensitivity to any vaccine component
  • Allergy to 2-phenoxyethanol, formaldehyde, neomycin, streptomycin, or polymyxin B

• OPV contraindications: 1

  • Immunocompromised persons (immune deficiency diseases, HIV infection, leukemia, lymphoma, immunosuppressive therapy)
  • Persons receiving antimicrobial agents (for oral Ty21a typhoid vaccine) 1

Special Populations

HIV-Infected Healthcare Workers

Enhanced IPV is the only poliovirus vaccine recommended for HIV-infected persons. 1

• Live OPV should never be administered to immunocompromised persons 1
• Killed/inactivated vaccines like IPV do not represent danger to immunocompromised workers 1
• Immune response may be suboptimal; higher doses or more frequent boosters may be required 1

Immunocompromised Persons

• Inactivated vaccines generally should be administered as recommended for non-immunocompromised persons 1
• Live virus or bacterial vaccines should not be administered 1
• Additional bacterial polysaccharide vaccines (Hib, pneumococcal, meningococcal) recommended for certain conditions 1

Common Pitfalls and Clinical Pearls

Documentation

• Only accept written documentation of vaccination 1
• Self-reported doses without written documentation should not be accepted 1
• Maintain complete immunization record for each person reflecting documented disease and vaccination histories 1

Catch-Up Vaccination

• Never restart a vaccine series regardless of time elapsed between doses 9, 6
• Intervals longer than recommended do not affect antibody titers 1
• Children with incomplete series should receive sufficient additional doses to complete series 3

Combination with Other Vaccines

• IPV should not be combined through reconstitution or mixed with any other vaccine 3
• Can be administered concomitantly with DTP, Hib, hepatitis B, or MMR using separate syringes at separate sites 3
• No immunological interference observed with these combinations 3

Policy Evolution

• US adopted all-IPV schedule in 1999 to eliminate VAPP cases 1, 3
• Sequential IPV/OPV schedule was intermediate step (1996-1999) 7
• OPV remains vaccine of choice in areas where wild poliovirus is still present due to superior intestinal immunity 1