What is Polio?

Polio (also known as Poliomyelitis)

An infectious disease that can be transmitted from person to person. Polio is caused by poliovirus, an enterovirus. Poliovirus is most well known for causing paralysis in young children.[0]

Poliovirus is part of the picornavirus viral family, a taxonomic grouping that includes other familiar viruses such as the rhino virus and hepatitis A virus. These viruses are most known for their icosahedral capsid(20 faces) structure that lacks a viral envelope and carries the positive-sense single stranded RNA genome. Further characteristics include being able to withstand low pH and thus able to pass through the stomach to infect and replicate in the intestinal epithelial cells and being incredibly infectious through the fecal-oral route. [0]

*funfact: Humans are the only natural hosts of this disease. Chimapanzees, Green African Monkeys etc can only be experimentally infected.

Whilst most infections are asymptomatic, viral particles that gain entrance into the central nervous system can replicate in neurons and destroy cells that govern muscle function resulting in flaccid paralysis.[0] To simply put it, the poliovirus invades the brain and spinal cord and may cause paralysis. However, 72 out of 100 infected people will not have any visible symptoms.[1]

Symptoms commonly include:
-Sore throat
-Fever
-Feeling lethargic
-Nausea
-Headache
-Stomach pains

More severe symptoms include:
-Paresthesia ( pins and needles in arms and legs or both)
-Meningitis (Inflammation of the brain & spinal cord)
-Paralysis or weakness of arms and legs

*Paralysis may be fatal due to the inactivation of muscles that aid in respiration. Hence Polio is often referred as a paralytic infection.

Poliovirus is easily transmitted through contact with an infected person. The virus lives in the infected person's throat and intestine. It enters the body though contact of feces and though less common, sneezes and coughs. Contamination of everyday items after not properly washing after using the toilet may speed up the infection rate. This is especially so in rural countries living in unsanitary conditions.

*The poliovirus may be cured with Oral Poliovirus Vaccine(OPV) or Inactivated Poliovirus Vaccine(IPV) but there are cases of Post-polio syndrome where patients recover after a vaccination but there happened to be a relapse of the patient's previous condition. [1]

Reference:
[0]Poliomyelitis. (n.d.). Retrieved July 31, 2015, from https://microbewiki.kenyon.edu/index.php/Poliomyelitis
[1] What Is Polio? (2014, October 15). Retrieved July 31, 2015, from http://www.cdc.gov/polio/about/

Research

The Global Polio Eradication Initiative is stressing on the importance of research against Polio to create and guide the world into a lasting polio-free world. The Global Polio Eradication Initiative coordinates and backs up an extensive programme of research from various core scientific disciplines with the 2 broad objectives f identifying, developing and evaluating new tools and tailored approaches to maximize the impact of eradication efforts as well as to inform long-term policies for the post-eradication era.

They currently support research areas including: Optimizing oral polio vaccine efficacy, Optimizing oral polio vaccine delivery, Developing affordable inactivated polio vaccine, Managing risks associated with vaccine-derived polioviruses and vaccine-associated paralytic polio (including Oral Polio Vaccine (OPV) cessation), Antivirus, Polio diagnostics and Surveillance research.[4]
Laboratory worker at containment hood
Their efforts were not wasted when it was reported that the "World is ready for OPV2 cessation" in 11 December 2014. At the October 2014 meeting, the Strategic Advisory Group of Experts on immunization (SAGE) - the independent body advising the World Health Organization(WHO) on immunization - concluded that preparations for the Oral Polio Vaccine type 2 (OPV2) withdrawal in early 2016 are on track. According to the article, this conclusion is of utmost importance in the success of Polio Eradication & Endgame Strategic Plan 2013-2018. The main aim was to remove the risk of cVDPV2 emerging by switching from trivalent OPV(containing type 1,2 and 3 serotypes) to bivalent OPV (containing only type 1 and 3 serotypes) in routine immunization programmes since   cVDPV2 had emerged in several countries in 2014 despite the wild poliovirus type 2 being eradicated since 1999. [5]
But what does this mean?                                                          

 There are plans to introduce inactivated polio vaccines (IPV) into the routine systems of 119 countries globally by the end of the year 2015. This marks one of the largest globally coordinated vaccine introduction projects in history. In order for this ambitious feat to be accomplished, all those countries will need to switch vaccines in the immunization programs carried out in April 2016. In a 2 week switch period, countries will decide on a National Switch Day in order to minimize the risk of a country continuing to use the trivalent OPV and inadvertently re-infecting other neighboring countries no longer using that particular vaccine.

The Global Polio Eradication Initiative is working closely with countries, regions, partners and manufacturers to ensure the vaccine supply is properly managed so as to gradually reduce the stck of trivalent OPVs that will eventually no longer be in use in the near future. This is to ensure that the trivalent OPVs remains in stock until the last day , countries of course would need to be cautious and arrange for service points as well as the proper disposal of stock. A one week buffer supply will be calculated and maintained to ensure that no child remains unimmunized during the switch week. [5]

As of 21 July 2015, WHO had put up a notice seeking consultants for the OPV expanded project in preparation for switch day. To see the application form, click Here.

[4] [http://www.polioeradication.org/Research.aspx] Research. (n.d.). Retrieved July 30, 2015.
[5][http://www.polioeradication.org/mediaroom/newsstories/World-ready-for-OPV2-cessation-/tabid/526/news/1181/Default.aspx?popUp=true] World ready for OPV2 cessation. (2014, December 11). Retrieved July 30, 2015.
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