Polio endgame: the global introduction of inactivated polio vaccine

Abstract

In 2013, the World Health Assembly endorsed a plan that calls for the ultimate withdrawal of oral polio vaccines (OPV) from all immunization programs globally. The withdrawal would begin in a phased manner with removal of the type 2 component of OPV in 2016 through a global switch from trivalent OPV to bivalent OPV (containing only types 1 and 3). To mitigate risks associated with immunity gaps after OPV type 2 withdrawal, the WHO Strategic Advisory Group of Experts has recommended that all 126 OPV-only using countries introduce at least one dose of inactivated polio vaccine into routine immunization programs by end-2015, before the trivalent OPV-bivalent OPV switch. The introduction of inactivated polio vaccine would reduce risks of reintroduction of type 2 poliovirus by providing some level of seroprotection, facilitating interruption of transmission if outbreaks occur, and accelerating eradication by boosting immunity to types 1 and 3 polioviruses.

Alternative administration routes and delivery technologies for polio vaccines

“…Although OPV is the most effective vaccine in endemic and high-risk areas to interrupt wild poliovirus transmission, the estimated number of polio cases caused by OPV now likely exceeds those related to wild polioviruses [53]. Wild type 2 poliovirus has not been detected since 1999 and the last case of wild type 3 was reported in November 2012.…”

“…Wild type 2 poliovirus has not been detected since 1999 and the last case of wild type 3 was reported in November 2012. For that reason, the Endgame Strategy aims for global cessation of type 2 OPV by switching from trivalent to bivalent OPV in routine immunization programs [53]. Such bivalent vaccines (type 1 and 3) are more immunogenic than trivalent OPV [54] and nearly as effective as the monovalent OPV formulations, especially in young children receiving their first polio immunization [55][56][57][58].…”

Eradication of Polio in the World; Iran is at Risk for Reemerging of Polio: A Review of the Literature

“…The key words were as follows: polio, poliomyelitis and polio eradication, OPV, IPV, AFP, VDP and Iran. One hundred and eighty-nine assessed abstracts included: polio and Iran (48), poliomyelitis and Iran (34), polio eradication and Iran (7), OPV and Iran (10), oral polio vaccine and Iran (18), IPV and Iran (12), inactivated polio vaccine and Iran (3), AFP and Iran (40), acute flaccid paralysis and Iran (15), VDP and Iran (0), and vaccine derived paralysis and Iran (2). Of these abstracts, 33 articles which were entirely relevant to the study goals were evaluated.…”

“…This program started with the removal of type 2 component of OPV in 2016. According to this program, before the above date (by the end of 2015), at least one dose of IPV vaccine is included in routine vaccination programs of all 126 countries that use OPV (10,18).…”

WHO Polio Eradication Program: Problems and Solutions

“…[8]. Ситуацию сегодняшнего дня образно называют «конец игры», что символизирует завершение длительного пути, который должен закончиться полной победой над поли-омиелитом [9][10][11]. Причины того, что выполнение про-граммы затянулось, различны: это и организационные проблемы в ряде стран [9][10][11], и особенности эпидеми-ческого процесса, который сегодня определяется как циркуляцией 1-го типа дикого вируса полиомиелита, так и циркуляцией возникших за эти годы вакцинородствен-ных штаммов [12][13][14].…”