WHO RAP Team: Perspective and Update WORKSHOP ON ANALYZING THE POLIO ERADICATION ENDGAME, Seattle, 1-2 July 2015

Data in WHO HQ as of 23 Jun 2015 Wild Poliovirus & cVDPV1 Cases2, Previous 6 Months 3 2 Excludes viruses detected from environmental surveillance. 3 Onset of paralysis 24 December 2014 – 23 June cVDPV is associated with ≥ 2 AFP cases or non-household contacts. VDPV2 cases have ≥ 6 (≥ 10 for type1) nucleotides difference from Sabin in VP1. Endemic country Wild poliovirus type 1 cVDPV type 2 WPV & cVDPV cVDPV type 1

 12 events in 8 countries Duration (months) – Median: 1.1 (range: , where 0=single case) 11/12 (92%) <6 months 1/12 (8%) >6 months Size of outbreak – 4 (33%) were single-case events (importations from Nigeria) – 8 (66%) were multiple-case events (median: 2 cases, range: 1-26 cases) cVDPV2 outbreaks,

 12 events 7 (58%) stopped spontaneously – 4 single-case events – 3 multiple-case events 1 (8%) stopped after 1 SIA 2 ( 17%) stopped after 2 SIAs 1 (8%) stopped after 3 SIAs 1 (8%) stopped after 8** SIAs cVDPV2 outbreaks, Impact of Response SIAs* *Number of SIAs during outbreak + 1 month following onset of last case **Chad – transmission widespread, but SIAs conducted in small areas each time, so multiple rounds to stop transmission nation-wide, but max 4 campaigns around any case

Endgame Plan, Polio detection & interruption (by 2014) Immunization systems & OPV withdrawal (by 2016) Containment & Certification (by 2018) Legacy Planning (by 2015)

What is the new endgame? Strategic framework for the sequential cessation of Sabin strains, starting with Sabin type 2. For Sabin type 2, cessation means that tOPV must be replaced with bOPV in a synchronized manner globally. For risk mitigation, the framework includes at least one dose of IPV included in the routine EPI (starting >6 months before switch from tOPV to bOPV).

Risks / Risk Mitigation Risk – rapidly decreasing mucosal immunity leads to multiple cVDPV emergences  eventual re- establishment of poliovirus circulation Risk mitigation – OPV2 withdrawal is globally synchronized – IPV will induce immunity base (mitigate the consequences of virus exposure) – mOPV2 stockpile in place for control activities – maintain possibility to restart tOPV production

Objectives of WHO RAP Team Accelerate eradication Support end- game Secure eradication Program assessment OPV Immunogenicity Assessment of role of IPV Innovations Assess role of IPV in routine immunization Coordinate development of endgame policies Facilitate licensure of IPV and bOPV Support to modelling groups Develop affordable IPV (Sabin IPV, ID IPV) Develop long-term options (VLP, non- infectious strains)

Some of WHO RAP Projects Acceleration of polio eradication – Short Interval Study – Immunogenicity of poliovirus vaccines in malnourished children Data on polio endgame – India EPI study – Pakistan mucosal study – Pakistan End Game Study – Nigeria IPV study Innovation – Trials to improve fIPV intradermal administration (adaptors, needle-free injectors, patches) – Support to Virus-like Particle developers, support to modellers Program evaluation (Seroprevalence surveys): – India, Nigeria, Pakistan, Madagascar, West Africa