Journal of Infectious Diseases
Volume 203 Issue 7 April 1, 2011
Eradication of Poliovirus: Fighting Fire With Fire
J Infect Dis. (2011) 203(7): 889-890 doi:10.1093/infdis/jiq148
Endemic wild polioviruses have been eliminated from most of the world, and the number of human paralytic cases has been reduced by >99%, from an estimated annual incidence of >500,000 cases to <2000 cases [ 1– 3]. Circulating wild polioviruses remain endemic in only 2 major locations, Nigeria and a zone extending from northern India west to Pakistan and Afghanistan [ 1– 3]. Furthermore, wild-type 2 poliovirus has been eliminated altogether, with the last documented case reported in northern India in 1999 [ 4]. These remarkable accomplishments represent a triumph for oral poliovirus vaccine (OPV), composed of attenuated variants of the 3 poliovirus serotypes [ 5]. OPV is administered by mouth, induces mucosal and humoral immunity, and is relatively inexpensive to produce—attributes that have contributed to its widespread use even in regions with rudimentary health systems.
However, OPV has an Achilles heel. The attenuated variants in the vaccine are rapidly replaced by revertant mutants, even on a single passage through the human intestine [ 6]. …