What is the most effective way to prevent and treat polio (poliomyelitis)?

Prevention and Treatment of Polio (Poliomyelitis)

Universal vaccination is the most effective way to prevent polio, with oral poliovirus vaccine (OPV) being the vaccine of choice for outbreak control and mass vaccination campaigns in endemic areas, while inactivated poliovirus vaccine (IPV) is preferred for routine immunization in polio-free countries. 1

Prevention Strategies

Routine Immunization

• Complete primary vaccination with three doses of poliovirus vaccine induces protective antibody levels to all three serotypes of poliovirus in >95% of recipients 1
• In polio-free countries like the United States, IPV is the recommended vaccine for routine immunization due to elimination of risk of vaccine-associated paralytic poliomyelitis (VAPP) 2
• Universal vaccination of infants and children is the only way to establish and maintain population immunity against polio since inapparent infection with wild poliovirus no longer contributes to immunity in polio-free regions 1

Outbreak Control Strategies

• OPV remains the vaccine of choice for mass vaccination to control polio outbreaks due to:

  • Higher seroconversion rates after a single dose compared to IPV
  • Greater intestinal immunity, limiting community spread of wild poliovirus
  • Beneficial secondary spread of vaccine virus, improving overall community protection 1

• During the 1996 polio outbreak in Albania, cases decreased 90% within 2 weeks after a single dose of OPV was administered to >80% of the population aged 0-50 years 1

• Even countries that rely on IPV for routine vaccination have used OPV for outbreak control, as demonstrated in the Netherlands (1992-93) and Finland (1984-85) 1

Global Eradication Strategies

• The following strategies have been implemented worldwide for polio eradication:

  • Achieving and maintaining high vaccination coverage with at least three doses of OPV among infants
  • Developing sensitive surveillance systems, including acute flaccid paralysis surveillance
  • Administering supplemental OPV doses during National Immunization Days
  • Conducting mopping-up vaccination campaigns in high-risk areas 1

• Mass vaccination campaigns are essential for polio eradication, achieving the highest possible coverage in the shortest time 3

Treatment Approaches

There is no specific antiviral treatment for polio once infection occurs. Management focuses on supportive care to address symptoms and prevent complications:

• Supportive measures for mild cases:

  • Rest
  • Pain management
  • Prevention of complications 4

• For severe cases with paralysis:

  • Hospitalization for respiratory support if respiratory muscles are affected
  • Physical therapy to prevent contractures and deformities
  • Orthopedic interventions for long-term sequelae 4

Special Considerations

Contraindications for OPV

• OPV should not be administered to:
  • Persons with immunodeficiency disorders
  • Persons who have experienced anaphylactic reactions to previous doses
  • Pregnant women (unless immediate protection is required) 1

Transition from OPV to IPV

• Due to the risk of vaccine-derived polioviruses (VDPVs), there has been a global transition from trivalent OPV to bivalent OPV (removing type 2) and introduction of at least one dose of IPV 2

• After eradication of wild poliovirus, IPV will need to replace OPV completely to sustain eradication of all polioviruses 5

Current Challenges

• Two significant challenges remain in global polio eradication:

  • Controlling outbreaks caused by vaccine-derived polioviruses
  • Increasing low immunization coverage in certain regions 4

• Wild poliovirus type 1 is likely the only wild poliovirus that remains in circulation, primarily in Afghanistan and Pakistan 4, 2

Pitfalls and Caveats

• Relying solely on IPV for outbreak control has historically shown limited effectiveness compared to OPV 1
• The risk of vaccine-associated paralytic poliomyelitis (VAPP) with OPV must be weighed against its benefits in outbreak settings 6
• Uncertainties remain about IPV's ability to induce intestinal immunity in populations where fecal-oral transmission is predominant 5
• Continued surveillance for polioviruses and prompt, aggressive responses to outbreaks are still needed even as global eradication approaches 2