Polio is rarely seen today, but that does not mean the global public health community can afford to become complacent. The complexity of the disease means that as long as one child in the world is infected with poliovirus, everyone remains at risk.
The risk of catching polio today has been greatly reduced thanks to the Global Polio Eradication Initiative (GPEI), launched in 1988 by the World Health Organization (WHO) and a coalition of partners. The GPEI’s ambitious goal of eliminating a disease that crippled more than 350,000 children across 120 countries has reduced the number of polio paralysis cases by 99.9 percent, with some 18 million people walking today who would have otherwise been paralyzed.1
In recent years, however, the disease has seen a resurgence in some parts of the world due to wars, unfavorable socio-economic conditions and the inability of some countries to provide all necessary vaccines. “We’ve had cause for concern over the last several years,” says Nadia Minarovic, global medical expert on polio and pediatric vaccines for Sanofi Pasteur. “There are reports from 20 countries around the world of new polio cases, from a total of 138 cases in 2018 to 541 in 2019 and expected increases again in 2020.2,3 This is really troubling and it’s important to sound the alarm that we cannot take our eyes off the polio fight.”
In addition, the COVID-19 pandemic has put millions of children at risk for several preventable childhood diseases, including polio. The WHO estimates that disrupted routine vaccination programs will impact at least 80 million children under the age of one.4
A complex infection
“Part of the reason why polio has been so hard to conquer is that the virus is transmitted among people through the digestive tract, is highly contagious and particularly difficult to manage if vaccines aren’t accessible,” said Nadia.
In most people, the body clears the polio virus without serious symptoms, but in approximately 10% of the population, mostly young children under five, poliovirus infection can cause fever, vomiting, and pain. One percent of those infected will experience irreversible paralysis or death.5,6
In many developing countries, public health programs use Oral Poliovirus Vaccines (OPV) that contain live but weakened viruses, followed by dose(s) of injectable Inactivated Poliovirus Vaccine (IPV). While injectable IPVs optimally prevent polio disease, OPVs help prevent transmission of poliovirus through the digestive tract and are often easier to administer in remote or underserved communities.
However, if oral poliovirus vaccine (OPV) schedules are not fully adhered to, it can cause serious complications. Where vaccination rates across communities are low, the attenuated live virus in the OPV can circulate within unimmunized people, mutating along the way and thereby eventually causing polio outbreaks.6
“That’s why, whatever option vaccinators are using, it’s absolutely critical that we help people fully complete the recommended number of doses for maximum individual and community protection against polio and minimum risks for outbreaks,” said Nadia. “High vaccination coverage rates will have to continue over time, too, to ensure polio never returns.”
For 40 years Sanofi Pasteur has supplied billions of polio vaccine doses, including hundreds of millions of donated doses to support eradication. The company continues to develop and deliver IPV doses worldwide and support polio vaccination programs.
Concludes Nadia, “We are so close to ending a global scourge as we know it, we cannot take our eye off the ball now.”
- http://polioeradication.org/who-we-are/our-mission/ last consulted July 29, 2020
- http://polioeradication.org/polio-today/polio-now/this-week/ consulted on June 2nd 2020
- http://polioeradication.org/polio-today/polio-now/this-week/circulating-vaccine-derived-poliovirus/ consulted on June 2nd 2020
- https://www.who.int/news-room/detail/22-05-2020-at-least-80-million-children-under-one-at-risk-of-diseases-such-as-diphtheria-measles-and-polio-as-covid-19-disrupts-routine-vaccination-efforts-warn-gavi-who-and-unicef last consulted September 3, 2020
- WHO Introduction to Poliomyelitis and the Global Polio Eradication Initiative https://openwho.org/courses/polio-introduction
- WHO factsheet updated on July 22nd 2019 https://www.who.int/news-room/fact-sheets/detail/poliomyelitis accessed June 2, 2020