Abstract
The global incidence of poliomyelitis has dropped by more than 99 per cent since the governments of the world committed to eradication in 1988. One of the three serotypes of wild poliovirus has been eradicated and the remaining two serotypes are limited to just a small number of endemic regions. However, the Global Polio Eradication Initiative (GPEI) has faced a number of challenges in eradicating the last 1 per cent of wild-virus transmission. The polio endgame has also been complicated by the recognition that vaccination with the oral poliovirus vaccine (OPV) must eventually cease because of the risk of outbreaks of vaccine-derived polioviruses. I describe the major challenges to wild poliovirus eradication, focusing on the poor immunogenicity of OPV in lower-income countries, the inherent limitations to the sensitivity and specificity of surveillance, the international spread of poliovirus and resulting outbreaks, and the potential significance of waning intestinal immunity induced by OPV. I then focus on the challenges to eradicating all polioviruses, the problem of vaccine-derived polioviruses and the risk of wild-type or vaccine-derived poliovirus re-emergence after the cessation of oral vaccination. I document the role of research in the GPEI's response to these challenges and ultimately the feasibility of achieving a world without poliomyelitis.
Highlights
Poliovirus is a small RNA virus, just 30 nm across and with a complete genome of only approximately 7500 nucleotides
Coordinated global cessation of oral poliovirus vaccine (OPV), 3 years after the last wild-virus-associated case of poliomyelitis was identified as a strategy that could minimize risks by stopping the introduction of vaccine poliovirus into the environment at a time when population immunity and the sensitivity of acute flaccid paralysis (AFP) surveillance are at their maximum [96]
The global eradication of serotype 2 wild poliovirus demonstrates the feasibility of eradicating all wild-type polioviruses
Summary
Poliovirus is a small RNA virus, just 30 nm across and with a complete genome of only approximately 7500 nucleotides. The ring vaccination strategy that was so successful in the final stages of smallpox eradication is not an option for the GPEI because poliovirus infection is typically far more widespread than the immediate social network of children with poliomyelitis Despite these limitations, AFP surveillance does permit high-risk areas for poliovirus transmission to be identified and targeted by SIA. Coordinated global cessation of OPV, 3 years after the last wild-virus-associated case of poliomyelitis was identified as a strategy that could minimize risks by stopping the introduction of vaccine poliovirus into the environment at a time when population immunity and the sensitivity of AFP surveillance are at their maximum [96]. Combination vaccines containing IPV, whole cell pertussis and other antigens are likely to be a sustainable option and are currently under development by a number of manufacturers [134]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
