By the end of 2014, three countries were still polio-endemic
There is no cure for polio but it can be prevented with a vaccine
First child in Nepal to be immunised with IPV as part of its introduction into the routine immunisation schedule, the first Gavi-supported country to do so.
Credit: UNICEF Nepal/2014
Crippling, potentially fatal
Polio is a highly contagious viral infection, mainly affecting children under the age of five, which can lead to paralysis or even death.
Many infected people have no symptoms but they excrete the virus, transmitting infection to others. In areas with poor sanitation, the virus easily spreads through contaminated water or food.
One in 200 infections leads to irreversible paralysis, usually in the legs. Among those paralysed, 5–10% die when their breathing muscles become immobilised.
Global Polio eradication efforts
Polio can only be prevented with a vaccine, as there is no cure. Multiple doses are required, usually providing life-long protection.
When the Global Polio Eradication Initiative (GPEI) was launched in 1988, polio was endemic in 125 countries and paralysed about 1,000 children per day. Thanks to global efforts and vaccination, polio cases have fallen by 99%, from more than 350,000 cases a year to 414 reported cases in 2014.
Today, more than 10 million people are walking who would otherwise have been paralysed by the poliovirus.1 India, once the world’s epicentre of polio, has been polio-free since January 2011. Only parts of three countries – Afghanistan, Nigeria and Pakistan – remain polio-endemic.
POLIO’S FINAL MILE
As long as a child anywhere remains infected with polio, children in all countries are at risk. Half of the polio cases in the 2009–2011 period resulted largely from weak immunisation and health systems, accessibility and security issues.2 In the past decade, polio has spread to over 20 polio-free countries from endemic areas.
Today, Pakistan and Afghanistan carry the burden of wild polio cases, but as outbreaks in Ukraine and Mali have shown, a weakened health system and persistent low immunisation coverage rates can quickly reverse the gains.
In May 2013, the World Health Assembly endorsed the new Polio Eradication & Endgame Strategic Plan 2013–2018, calling on countries to introduce at least one dose of the inactivated polio vaccine (IPV) and begin the phased removal of oral polio vaccines (OPV).
In the next phase, all countries will switch from the trivalent OPV to the bivalent OPV in April 2016 – removing the type 2 component of the vaccine as type 2 wild poliovirus has already been eradicated. This, in turn, will lead to the complete removal of the live-attenuated oral vaccine, which is necessary to eliminate the risk of vaccine-associated polio outbreaks.
The introduction of IPV is a critical step to manage potential risks associated with this phased removal. Adding IPV to routine immunisation programmes will improve immunity and help to prevent further OPV-associated outbreaks from emerging.
Overcoming the final 1% of cases is similar to completing a marathon – the final stretch is often the most difficult to complete, takes the most focused effort and yet can be the most rewarding.
A 2010 study3 estimates that polio eradication could provide at least US$ 40–50 billion in net benefits for the world’s poorest countries, primarily from avoided treatment costs and productivity gains.
The Global Polio Eradication Initiative (GPEI) is a public-private partnership led by national governments and spearheaded by WHO, Rotary International, the US Centers for Disease Control and Prevention (CDC), and UNICEF. Its goal is to eradicate polio worldwide.
1GPEI Polio Eradication & Endgame Strategic Plan 2013 -2018, chapter 4
2 GPEI Polio Eradication & Endgame Strategic Plan 2013 -2018, p9
3 Duintjer Tebbens RJ, Pallansch MA, Cochi SL, Wassilak SGF, Linkins J, Sutter RW, Aylward RB, Thompson KM. Economic analysis of the Global Polio Eradication Initiative. Vaccine 2011;29(2):334-343.