Poliomyelitis Virus

Poliomyelitis Virus Full Name

Poliomyelitis Virus

Poliomyelitis Virus Introduction

Poliovirus is the virus responsible for causing polio, a disease also known as poliomyelitis. It belongs to the Enterovirus C species in the Picornaviridae family. The virus consists of a single-stranded RNA genome and a protein capsid. The genome is made up of positive-sense RNA and is approximately 7500 nucleotides long. The viral particle itself has a diameter of around 30 nanometers and exhibits icosahedral symmetry. Poliovirus is often considered the simplest significant virus and a useful model system for understanding the biology of RNA viruses due to its compact genome and basic composition, consisting only of RNA and a non-enveloped protein coat.

Figure 1. Structural features of poliovirus.
(Source: Levy, H. C. et al., 2010)

Polioviruses are classified into three serotypes: PV1, PV2, and PV3. Each serotype can cause polio, but they differ in terms of symptom severity and prevalence. PV1 is associated with severe symptoms, PV2 with milder symptoms, and PV3 is rare but can also cause severe symptoms. During the mid-20th century, polio epidemics reached their peak in many countries, causing thousands of cases of paralysis and death. The virus primarily spreads through the fecal-oral route, usually through contaminated water or food. Polio outbreaks often occured during the summer months, leading to widespread fear and panic among the population.

Two types of vaccines are widely used to combat polio globally. The Salk vaccine, also known as the inactivated poliovirus vaccine (IPV), is based on three wild, virulent reference strains of polioviruses (Mahoney, MEF-1, and Saukett). These strains are grown in a type of monkey kidney tissue culture called the Vero cell line. The viruses are then inactivated using formalin, making them safe for use as a vaccine. The oral polio vaccine (OPV), also known as Sabin's vaccine, is a live-attenuated vaccine. It is produced by passing the virus through non-human cells at a sub-physiological temperature. This process causes spontaneous mutations in the viral genome, reducing its virulence while retaining its ability to stimulate an immune response. The use of these vaccines has been instrumental in reducing the global burden of polio. Vaccination campaigns, along with surveillance and containment efforts, have led to significant progress in eradicating the disease.

Alternate Names for Poliomyelitis Virus

Poliomyelitis Virus;Poliovirus

• 1. Levy H C, et al. Catching a virus in the act of RNA release: a novel poliovirus uncoating intermediate characterized by cryo-electron microscopy. Journal of Virology. 2010, 84(9): 4426-4441.
  2.Shaw A G, et al. Sensitive poliovirus detection using nested PCR and nanopore sequencing: a prospective validation study. Nature Microbiology. 2023, 8(9): 1634-1640.