Lessons From Globally Coordinated Cessation of Serotype 2 Oral Poliovirus Vaccine for the Remaining Serotypes
by Kimberly M. Thompson and Radboud J. Duintjer Tebbens, Journal of Infectious Diseases 2017; 216(S1):S168-S175 doi:10.1093/infdis/jix128.

What are the study’s main findings?
What are the study’s main recommendations?
Background on polio

What are the study’s main findings?

• Modeling of oral poliovirus vaccine (OPV) serotype 2 (OPV2) cessation suggested rapid die-out of OPV2-related viruses after cessation, as occurred in most countries, except in (i) Pakistan/Afghanistan, which chose not to intensify supplemental immunization activities (SIAs) using trivalent OPV (tOPV) prior to OPV2 cessation, (ii) areas with significant security and/or quality issues such as northern Nigeria, and (iii) areas that probably used tOPV inadvertently after OPV2 cessation.
• The experience at 6 months after globally-coordinated OPV2 cessation appears broadly consistent with model expectations, except for programmatic failures.
• Partially-diverged OPV2-related viruses detected between 6-12 months after OPV cessation may still die out, although it is too early to tell if they will result in outbreaks. OPV2-related viruses that persist for longer than a year will most likely go on to cause an outbreak of a circulating vaccine-derived poliovirus (cVDPV).
• Failing to respond to confirmed cVDPV2 outbreaks implies a high risk of needing to restart the use of OPV2 in countries that currently use OPV.
• Using monovalent OPV serotype 2 (mOPV2) to respond to serotype 2 outbreaks that occur during the first 5 years after OPV2 cessation represents the best strategy to contain the outbreak, and using inactivated poliovirus vaccine (IPV) instead of mOPV2 for outbreak response significantly increases the probability of needing to restart OPV2 in countries that currently use OPV.
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• Countries that use OPV should use mOPV2 aggressively to respond to confirmed serotype 2 polio outbreaks as long as that option exists.
• Countries should recognize that failing to stop transmission of a poliovirus causing cases represents a much greater threat than using the much less transmissible and less virulent OPV for outbreak response.
• Using IPV for outbreak response in OPV-using countries will probably not stop the outbreak and does not represent a cost-effective use of IPV.
• Ensuring a successful polio endgame requires more aggressive OPV cessation risk management than occurred to date for OPV2 cessation, which should include maintaining high population immunity to transmission up until bivalent OPV (bOPV) cessation, meeting all prerequisites for bOPV cessation, and ensuring sufficient vaccine supply to prevent and respond to outbreaks.
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