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Poliovirus

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Key Points

  • Poliovirus
    • Member of Picornavirus family
    • Presentation
      • Poliomyelitis
        • Damages motor neurons of anterior horns of spinal cord
          • Causes LMN disease: flaccid paralysis, atrophy, areflexia, fasciculations
    • Vaccination
      • Live-attenuated oral vaccine (OPV)
        • Also called the Sabin vaccine
        • Stronger IgA response (than Salk)
          • Detected in oropharyngeal and intestinal mucosa
          • Secretory IgA inhibits viral entry at GI mucosa
        • Rare vaccine-associated paralytic poliomyelitis (VAPP)
          • Occurs in 1 in 1 million people vaccinated
          • For this reason, IPV is preferred in developed countries with low polio rates (cost > benefit)
          • In developing countries, OPV is still used due to lower cost and greater efficacy (cost < benefit)
      • Inactivated (Salk) vaccine (IPV)
        • Only IPV is approved for use in USA, since no VAPP risk compared to OPV