World Health Organization (WHO) on Twitter: "#Polio cases worldwide: 1988: 350000 2016: 27 That's a ⬇ of more than 99.9% #VaccinesWork! Let's #EndPolio #WorldPolioDay https://t.co/bvvHTOFA7b" / Twitter
Risk factors for the spread of vaccine-derived type 2 polioviruses after global withdrawal of trivalent oral poliovirus vaccine and the effects of outbreak responses with monovalent vaccine: a retrospective analysis of surveillance
Poliomyelitis, 1789-2016
File:Polio worldwide 2016.svg - Wikimedia Commons
Historic Global Vaccine Rollout Could End Polio Forever | Time
The Unfolding of Polio - The New York Times
Our history: Sabin and Salk competed for safest polio vaccine
Two New Polio Cases In Nigeria Are The First Detected In Africa In More Than Two Years : Goats and Soda : NPR
Attacks Hamper Pakistan's Efforts on Polio – The Diplomat
Polio eradication faces setback as Nigeria records first cases in two years | Nature
Joint Statement on World Polio Day 2016 – UNICEF Ethiopia
N.Y. state detects polio case, first in the U.S. since 2013