Focusing on population immunity to transmission to manage pre-OPV cessation risks of cVDPVs, all countries performing poliovirus SIAs should use tOPV up until the time of OPV2 cessation, after which time they should continue to use the OPV vaccine formulation with all remaining serotypes until coordinated global cessation of those serotypes.
Focusing on population immunity to transmission to interrupt WPV1 transmission and manage pre-OPV cessation risks of cVDPVs, all countries performing poliovirus SIAs should use tOPV up until the time of OPV2 cessation, after which time they should continue to use the OPV vaccine formulation with all remaining serotypes until coordinated global cessation of those serotypes.
We also consider the impact of a failure to intensify tOPV use leading up to OPV2 cessation, which assumes continuation of the SIA schedule from before the year 2015 up until the time of OPV2 cessation (Additional file 1).
Our analyses suggest that all countries performing polio SIAs should use tOPV up until the time of OPV2 cessation, after which time they should continue to use the OPV vaccine formulation with all remaining serotypes until coordinated global cessation of those serotypes as they manage population immunity to transmission.
He had played a very crucial role in the build up to the cessation, in particular by supporting a visa for me.
In an interview, Mr. Passel agreed that though departures were probably up somewhat, "the cessation of growth in the unauthorized population is due to the decline in arrivals".
So what we want to see is the regime to comply with the cessation of hostilities, which only applies to those who have signed up to the cessation of hostilities".
Consequently, maximizing population immunity just prior to OPV cessation of any given serotype(s) requires high homotypic OPV use up until OPV cessation [ 13, 21].
However, as with OPV2 cessation, continued SIAs with OPV containing serotypes 1 and 3 up until OPV13 cessation remain necessary in populations with low RI coverage to prevent subsequent cVDPV1 and cVDPV3 outbreaks.
Based on the scenario of no reduction in SIA frequency after OPV2 cessation (not currently planned by the GPEI and not needed based on our results), bOPV needs remain very high up until OPV13 cessation, with a total of 8.0 billion doses between January 1 , 2016and April 1 , 2019 and SIAs accounting for 71%% of the total.
