POLIO [to 5 March 2016]
Public Health Emergency of International Concern (PHEIC)

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Polio this week as of 2 March 2016
:: The Director General of WHO, Dr Margaret Chan, upon the advice of the Emergency Committee, concluded that poliovirus continues to constitute a Public Health Emergency of International Concern (PHEIC). Read the statement here [and below]
:: The Journal of Infectious Diseases has published a supplemental journal on Nigeria’s polio eradication effort. Read more here.
:: A new method to administer the inactivated poliovirus vaccine (IPV), developed by a collaboration of Australian institutions, has had promising results in animal trials. The Nanopatch may enable unprecedented levels of dose reduction.
:: There are seven weeks to go until the globally synchronized switch from the trivalent to bivalent oral polio vaccine

Selected Country Levels Updates [excerpted]
Pakistan
:: Three new cases of wild poliovirus type 1 (WPV1) were reported in the last week, in Quetta, Balochistan, and the districts of Hangu and Peshawar in Khyber Pakhtunkhwa, with onset of paralysis between 1 and 12 February. The total number of WPV1 cases for 2016 is now 5, compared to 13 reported for 2015 at this point last year.
:: Four new WPV1 environmental positive samples were reported in the past week; one in Faisalabad, Punjab; two in Karachi Gadap, Sindh; and one in Peshawar, Khyber Pakhtunkhwa; with collection dates between 3 and 10 February.

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Statement on the 8th IHR Emergency Committee meeting regarding the international spread of poliovirus
WHO statement
1 March 2016
[Excerpts; Editor’s text bolding]

The eighth meeting of the Emergency Committee under the International Health Regulations (2005) (IHR) regarding the international spread of poliovirus was convened via teleconference by the Director-General on 12 February 2016. As with the seventh meeting, the Emergency Committee reviewed the data on circulating wild poliovirus as well as circulating vaccine-derived polioviruses (cVDPV). The latter is particularly important as cVDPVs reflect serious gaps in immunity to poliovirus due to weaknesses in routine immunization coverage in otherwise polio-free countries. In addition, it is essential to stop type 2 cVDPVs in advance of the globally synchronized withdrawal of type 2 OPV in April 2016.

The following IHR States Parties submitted an update on the implementation of the Temporary Recommendations since the Committee last met on 10 November 2015: Afghanistan, Pakistan and Guinea.

Wild polio
The Committee noted that since the declaration that the international spread of polio constituted a Public Health Emergency of International Concern (PHEIC) in May 2014, strong progress has been made by countries toward interruption of wild poliovirus transmission and implementation of Temporary Recommendations issued by the Director-General. There has been an overall decline in the occurrence of international spread of wild poliovirus. The Committee was particularly encouraged by the intensified efforts and progress toward interruption of poliovirus transmission in Pakistan and Afghanistan despite challenging circumstances, and the renewed emphasis on cooperation along the long international border between the two countries.

The Committee noted however that the international spread of wild poliovirus has continued, with two new recent reports of exportations from Pakistan into Afghanistan which occurred in October and November 2015. These cases occurred in Nangarhar and Kunar Provinces, in the eastern region, adjoining the Pakistan border. While there has been no new exportation from Afghanistan to Pakistan, ongoing transmission particularly in inaccessible parts of the Eastern Region of Afghanistan close to the international border presents an ongoing risk.

The Committee noted that while Pakistan and Afghanistan have historically shared a vast common zone of poliovirus transmission, the ongoing spread between the two countries is occurring from discrete zones of persistent transmission in each country. Strong programmatic action in these zones should interrupt such cross-border transmission, as illustrated by the experience in regions that were previously polio-endemic.

The committee re-emphasized that under the IHR, spread of poliovirus between two Member States can constitute international spread. The Committee acknowledged that cross border collaboration efforts have continued to be strengthened. Whilst border vaccination between these two countries is limited to children under ten years of age, efforts are being made to vaccinate departing travellers of all age groups from airports when leaving this epidemiological block formed by the two countries. The committee was particularly pleased that the Temporary Recommendations for international travellers of all ages are now being implemented in Afghanistan at the international airport in Kabul. In this respect, it noted that all countries, and particularly those with embassies in Afghanistan and Pakistan, should facilitate implementation of Temporary Recommendations through adopting procedures that include proof of polio vaccination as part of visa application processes for travellers departing from Afghanistan or Pakistan.

The committee noted that globally there are still significant vulnerable areas and populations that are inadequately immunized due to conflict, insecurity and poor coverage associated with weak immunization programmes. Such vulnerable areas include countries in the Middle East, the Horn of Africa, central Africa and parts of Europe. The hard-earned gains of the GPEI can be quickly lost if there is re-introduction of poliovirus in settings of disrupted health systems and complex humanitarian emergencies. The large population movements across the Middle East and from Afghanistan and Pakistan create a heightened risk of international spread of polio. There is a risk of missing polio vaccination among refugee and mobile populations, adding to missed and under vaccinated populations in Europe, the Middle East and Africa. An estimated three to four million people have been displaced to Turkey, Lebanon, and Jordan and are at the centre of a mass migration across Europe.

The committee was very concerned by the weakening of AFP surveillance in Equatorial Guinea, and urged renewed efforts to strengthen surveillance and routine immunization there. Insecurity in Africa, notably in parts of Cameroon and Somalia, continues to pose a threat to polio eradication in that continent.

Vaccine derived poliovirus
The current circulating vaccine-derived poliovirus (cVDPV) outbreaks across four WHO regions illustrate serious gaps in routine immunization programs, leading to significant pockets of vulnerability to polio outbreaks. In 2015, six outbreaks of circulating vaccine derived poliovirus have occurred – three cVDPV type 1 outbreaks (Ukraine, Madagascar and Lao People’s Democratic Republic) and three cVDPV type 2 outbreaks (Myanmar, Nigeria and Guinea).

Six additional cases of cVDPV type 2 have been reported in Guinea since the last meeting. This increases the threat of international spread, particularly to neighbouring countries, where the Ebola epidemic has weakened health systems including routine immunization. This is of particular concern given the imminent global withdrawal of type 2 oral polio vaccine (OPV2) in April 2016. The committee noted with concern that AFP surveillance does not meet international standards in parts of Guinea, heightening concern about whether circulation could be missed. Post-Ebola there was a new community reluctance to accept vaccination, and this needs to be urgently addressed. The committee acknowledged the efforts to improve the quality of supplementary immunization activities (SIAs), and urged that this continue.

The committee noted that in Lao People’s Democratic Republic and Myanmar there was ongoing circulation of vaccine derived polioviruses, particularly in hard to reach populations in both countries, underlining the importance of communication to counteract vaccine hesitancy.

While there have been no new cases of cVDPV in Ukraine, Madagascar, South Sudan or Nigeria since the last committee meeting, threats remain. More needs to be done in each of these countries to improve routine coverage and AFP surveillance. In Ukraine, the committee was concerned by the restricted availability of polio vaccines (including non-availability to persons >10 years of age) and suboptimal routine immunization, and reports of lack of community acceptance of polio vaccines. This reluctance to be vaccinated needs to be addressed through well-crafted communications. In South Sudan and Nigeria, there was heightened risk of further circulation in areas affected by conflict and insecurity. Complacency is another risk in Nigeria, and as the number of SIAs decreases, the strengthening of routine immunization needs to be a high priority.

Conclusion
The Committee unanimously agreed that the international spread of polio remains a Public Health Emergency of International Concern (PHEIC) and recommended the extension of the Temporary Recommendations for a further three months. The Committee considered the factors expressed in reaching this conclusion at the seventh meeting still applied:
:: The continued international spread of wild poliovirus during 2015 involving Pakistan and Afghanistan.
:: The risk and consequent costs of failure to eradicate globally one of the world’s most serious vaccine preventable diseases.
:: The continued necessity of a coordinated international response to improve immunization and surveillance for wild poliovirus, stop its international spread and reduce the risk of new spread.
:: The serious consequences of further international spread for the increasing number of countries in which immunization systems have been weakened or disrupted by conflict and complex emergencies. Populations in these fragile states are vulnerable to outbreaks of polio. Outbreaks in fragile states are exceedingly difficult to control and threaten the completion of global polio eradication during its end stage.
:: The importance of a regional approach and strong cross-border cooperation, as much international spread of polio occurs over land borders, while recognizing that the risk of distant international spread remains from zones with active poliovirus transmission.
:: Additionally with respect to cVDPV:
::: cVDPVs also pose a risk for international spread, and if there is no urgent response with appropriate measures, particularly threaten vulnerable populations as noted above;
::: The emergence and circulation of VDPVs in four WHO regions demonstrates significant gaps in population immunity at a critical time in the polio endgame;
::: There is a particular urgency of stopping type 2 cVDPVs in advance of the globally synchronized withdrawal of type 2 component of the oral poliovirus vaccine in April 2016.