The oral polio vaccine and inactivated polio vaccine are being used in the quest to eradicate polio. Vaccination remains the only way to achieve a polio-free world.
Types and status
There are three types of wild polio virus, namely wild polio virus type 1 (WPV1), wild polio virus type 2 (WPV2) and wild polio virus type 3 (WPV3). WPV2 circulation stopped globally more than 15 years ago and no WPV3 cases have been reported since November 2012 anywhere in the world. In March 2014, after three years of no cases in India, the World Health Organisation (WHO) South East Asia Region (SEARO) was certified polio-free. As a result of collaborative partnership efforts of immunisation, all recent outbreaks in the Horn of Africa, Central Africa and Middle East stopped in mid-August 2014. No WPV cases of any type have been reported in Africa since 11 August 2014. This good news is the result of the combined use of oral polio vaccine (OPV) and inactivated polio vaccine (IPV) in areas with security challenges and in outbreak settings, such as Afghanistan, Kenya, Cameroon, Nigeria and Pakistan.
What happens?
Poliomyelitis is a highly infectious viral disease that spreads from person to person, mostly through contaminated food or water. The virus inhabits the intestinal tract where it multiplies and from where it attacks the nervous system. Fatigue, fever, headache, neck stiffness and limb pain are the initial symptoms. In about 5% of cases the virus causes non-reversible paralysis, mostly in the legs. Among those paralysed, 5 to 10% could die due to paralysis of the breathing muscles.
Polio is the greatest cause of disability through the history of the world. It affects mostly children under the age of 5. There is no cure and vaccination remains the only way to combat the disease.
Vaccination
Vaccination against polio is inexpensive. It costs approximately R5 to vaccinate a child with oral poliovirus vaccine (OPV) and the vaccine provides protection against polio for life. The oral polio vaccine contains live polio viruses and in rare instances this might cause new outbreaks of the illness. To combat this, an inactivated polio vaccine can now be given in the form of injections in countries where wild polio has been eradicated.
The main reason for the sporadic outbreaks of polio is that not all children in some areas and even no children in remote areas have been vaccinated against polio. The vaccination programme therefore has to continue in these areas.
The drop in cases of polio has been the result of a global drive by the World Health Organisation (WHO), the Rotary Foundation, the United Nations Children’s Fund (Unicef) and the American Centre for Disease Control and Prevention (CDC). Their Global Polio Eradication Initiative (GPEI) was launched in 1988 with the aim of eradicating polio. South Africa participates in the drive to eradicate polio with a childhood vaccination programme available to all citizens. Four vaccinations are given, the first at 2 months, second at 4 months, third at 6–18 months and the fourth at 4–6 years of age.
Sources
Africa on brink of polio eradication. Retrieved from: https://www.rotary.org/en/news-media/africa-brink-polio-eradication
Inactivated polio vaccine. Retrieved from: http://www.polioeradication.org/Polioandprevention/Thevaccines/Inactivatedpoliovaccine%28IPV%29.aspx
Polio eradication and endgame. Retrieved from: http://www.polioeradication.org/Portals/0/Document/Resources/StrategyWork/GPEI-MTR_July2015.pdf
(Revised by M van Deventer)