Polio Update as of February 24, 2016

 
 
Polio this week as of 24 February 2016
 
  • GPEI have published six new videos on ‘Securing a Polio Free World’ covering topics including the polio vaccines, circulating vaccine-derived polioviruses and the upcoming ‘Switch’. The videos are available in both English and French.
  • There are eight weeks to go until the globally synchronized switch from the trivalent to bivalent oral polio vaccine, an important milestone in achieving a polio-free world. Read more about the reasons behind the switch here. Read more ongoing preparation for the switch here.
     
     
      
    Wild poliovirus type 1 and Circulating vaccine-derived poliovirus cases
Total cases
Year-to-date 2016
Year-to-date 2015
Total in 2015
WPV
 cVDPV
 WPV
 cVDPV
 WPV
 cVDPV
Globally
2
2
10
0
74
31
- in endemic countries
2
0
10
0
74
 3
- in non-endemic countries
0
2
0
0
0
 28
 
 
Case breakdown by country
 
Countries
Year-to-date 2016
Year-to-date 2015
Total in 2015
Onset of paralysis of  most  recent case
WPV
cVDPV 
WPV 
cVDPV
 WPV
cVDPV 
 WPV
 cVDPV
Afghanistan
0
0
1
0
20
0
20-Dec-15
NA
Pakistan 
2
0
9
0
54
2
22-Jan-16
09-Feb-15
Guinea
0
0
0
0
0
7
NA
14-Dect-15
Lao PDR
 0
2
0
0
0
7
NA
11-Jan-16
Madagascar
0
0
0
0
0
10
NA
22-Aug-15
Myanmar
0
0
0
0
0
2
NA
05-Oct-15
Nigeria
0
0
0
0
0
1
NA
16-May-15
Ukraine
0
0
0
0
0
2
NA
07-Jul-15

NA: onset of paralysis in most recent case is prior to 2015. Figures exclude non-AFP sources. Madagascar, Ukraine and Lao PDR cVDPV1, all others cVDPV2. cVDPV definition: see document "Reporting and classification of vaccine-derived polioviruses" at http://www.polioeradication.org/Portals/0/Document/Resources/VDPV_ReportingClassification.pdf. Implementation as of 15 August 2015.
- See more at: http://www.polioeradication.org/Dataandmonitoring/Poliothisweek.aspx#sthash.X7vOVRBF.dpuf
 
Afghanistan
  • No new wild poliovirus type 1 (WPV1) case was reported in the past week. The most recent case reported onset of paralysis in Shahwalikot, Kandahar, on 20 December 2015.
  • No new WPV1 environmental positive samples were reported in the past week. The most recent environmental positive samples were collected on 27 December 2015 - one in Jalalabad in Nangarhar province and the second in the city of Kabul.
  • National Immunization Days (NIDs) are planned from 15 to 18 March, prior to the switch. Read more about the switch here.
     
    Pakistan
  • One new case of wild poliovirus type 1 (WPV1) was reported in the last week, in Nowshera, Khyber Pakhtunkhwa, with onset of paralysis on 22 January. The total number of WPV1 cases for 2016 is now 2, compared to 9 reported for 2015 at this point last year. 
  • One new WPV1 environmental positive was reported in the past week in Karachi Gadap, Sindh province, with collection on 27 January. 
  • National Immunization Days (NIDs) are planned in March using tOPV.
    - See more at: http://www.polioeradication.org/Dataandmonitoring/Poliothisweek.aspx#sthash.X7vOVRBF.dpuf
  •  
    Friday, December 18, 2015
    Stopping vaccine-derived polioviruses
    With four months to go until the global switch from trivalent to bivalent oral polio vaccine, we are nearing an important milestone in the journey to a polio-free world
     
     
    In just four months’ time, the world will embark on one of the most ambitious globally synchronised projects in the history of vaccines. April 2016 will see 155 countries and territories stop using the trivalent oral polio vaccine (OPV) and switch to the bivalent version of the vaccine, in a single two week period. This will have an important impact on progress towards achieving the eradication of all polioviruses worldwide.
    Stopping vaccine-derived polioviruses
    In 2015, more countries were infected by vaccine-derived polioviruses (VDPVs) than wild polio (WPV). VDPVs are very rare strains of polio that can mutate from the weakened poliovirus in the oral polio vaccine when levels of immunization are very low, allowing the vaccine virus to circulate amongst unprotected children for an extended period of time. Learn more about VDPVs here.
    As we approach eradication, the proportion of the contribution that cVDPVs make to the global burden of all polio cases increases. In large part, this is a consequence of the diminishing burden posed by WPV, therefore representing our progress to date. Yet it also highlights the fact that in too many areas of the world, too many children continue to go unvaccinated, leaving them vulnerable to WPV and allowing VDPVs to emerge.
    The oral polio vaccine has brought us a tremendous distance towards achieving our goal of polio eradication, demonstrated by the declaration of WPV type 2 as eradicated in September 2015. Wild poliovirus remains endemic in just two countries in the world – Afghanistan and Pakistan – with cases of only one strain of wild polio, type 1, being found globally. This could not have been achieved without the oral polio vaccine’s ability to protect children, to stop the virus circulating between individuals, and the ease with which it can be delivered even by community volunteers without medical training.
    Withdrawing oral polio vaccine type 2
    With the eradication of wild poliovirus type 2, the type 2 component of the oral polio vaccine is no longer needed. This is good news for children and the polio eradication programme, as the type 2 component of the oral polio vaccine has caused 90 % of circulating VDPV outbreaks in recent years. By switching from the trivalent vaccine (which contains protection against all three strains) to the bivalent vaccine which no longer contains type 2, we therefore withdraw the main cause of VDPVs and take the programme an important step forward towards eradication.