5 reasons why polio can be eradicated
Jul. 29, 2019
We know that we can and we will eradicate polio, but how do we know that? Only one human disease has ever been eradicated—that’s smallpox. What makes a disease a good candidate for eradication?
Poliovirus causes acute, non-persistent infections
The virus causes acute, short term infections, meaning that a person infected with polio can only transmit the virus for a limited amount of time. Prolonged infection with wild polioviruses has never been documented and in most cases infected people can only transmit the virus for 1-2 weeks.
Virus is transmitted only by infectious people or their waste
Some diseases can be transmitted in a multitude of ways, which can make a disease an impossible candidate for eradication. But the poliovirus is typically transmitted just one way: through human waste. Eradicating polio is not an easy task, but the way polio is transmitted simplifies our ability to tackle the disease.
Survival of virus in the environment is finite
Did you know there’s just one strain of wild poliovirus that continues to infect humans? (There used to be three strains of poliovirus that regularly infected humans.) The wild poliovirus cannot survive for long periods outside of the human body. If the virus cannot find an unvaccinated person to infect, it will die out. This is why we have to keep every single child vaccinated—so the virus cannot find any humans to infect. The length of poliovirus survival varies according to conditions like temperature, and the poliovirus infectivity decreases over time.
People are the only reservoir
Hundreds of diseases can be transmitted between insects, animals and humans. One of the things that makes polio eradicable is the fact that humans are the only reservoir. No poliovirus has been found to exist and spread among animals despite repeated attempts to document this.
Immunization with polio vaccine interrupts virus transmission
Not only are there two safe and effective polio vaccines, but vaccination against polio generates herd immunity, which increases the percentage of the population that is immune to the disease.
Mass campaigns using oral polio vaccine, where all children in a specified geographic area are immunized simultaneously, interrupts wild poliovirus circulation by boosting population immunity to the point that transmission of polio cannot be sustained.
One additional way we know we’ll eradicate polio is that we’ve eliminated polio in nearly every single country in the world—even in countries like in India, which as recently as 2007 was home to 70% of the world’s poliovirus cases. There are just two countries that continue to report wild poliovirus transmission, and we’re certain we have the tools and scientific know-how to eliminate polio in the remaining two countries. Donate to the cause or follow us on Facebook to learn more about how Rotary is working with our partners to #endpolio.