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WHO RAP Team:
Perspective and Update
WORKSHOP ON ANALYZING THE POLIO ERADICATION ENDGAME,
Seattle, 1-2 July 2015
Wild Poliovirus & cVDPV1 Cases2, Previous 6 Months3
WPV & cVDPV
cVDPV type 1
Wild poliovirus type 1
cVDPV type 2
Onset of most
recent case
Country
Number Total
Total
of
WPV
cVDPV
infected (All
(All type1)
districts type1)
2
0
5
Madagascar
03-May-15
AFR
03-May-15
2
0
5
Pakistan
24-May-15
15
26
0
is associated with ≥ 2 AFP cases or non-household contacts. VDPV2 cases
have ≥ 6 (≥ 10 for type1) nucleotides difference from Sabin in VP1.
Afghanistan
05-May-15
3
4
0
EMR
24-May-15
18
30
0
2Excludes
Global
24-May-15
18
30
5
3Onset
NA: most recent case had onset of paralysis
Endemic country
1cVDPV
viruses detected from environmental surveillance.
of paralysis 24 December 2014 – 23 June 2015
Data in WHO HQ as of 23 Jun 2015
Circulating Persistent cVDPV2
Nigeria
Pakistan
(last case: 16-Nov-2014, last ENV isolate: 4-Mar-2015)
(last case: 13-Dec-2014, last ENV isolate: 28-Mar-2015)
cVDPV2 outbreaks, 2010-2015
12 events in 8 countries
• Duration (months)
– Median: 1.1 (range: 0 - 9.7, 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, 2010-2015
Impact of Response SIAs*
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
*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, 2013-18
• 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 reestablishment 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
• Program assessment
• OPV
Immunogenicity
• Assessment of role
of IPV
• Innovations
Support endgame
• Assess role of IPV in
routine
immunization
• Coordinate
development of
endgame policies
• Facilitate licensure of
IPV and bOPV
• Support to modelling
groups
Secure
eradication
• Develop affordable
IPV (Sabin IPV, ID
IPV)
• Develop long-term
options (VLP, noninfectious 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