Following its statement declaring that the recent international spread of polio is to be treated as a Public Health Emergency of International Concern, WHO has also issued guidelines and international requirements for countries that have been identified as particularly high-risk. These countries are Pakistan, Cameroon and the Syrian Arab Republic, and the recommendations state that countries should: “Ensure that all residents and long-term visitors receive a dose of oral polio vaccine (OPV) or inactivated poliovirus vaccine (IPV) between four weeks and 12 months prior to international travel; ensure that those undertaking urgent travel (i.e. within four weeks), who have not received a dose of OPV or IPV in the previous four weeks to 12 months, receive a dose of polio vaccine at least by the time of departure as this will still provide benefit, particularly for frequent travellers; [and] ensure that such travellers are provided with an International Certificate of Vaccination or Prophylaxis in the form specified in Annex 6 of the International Health Regulations (2005) to record their polio vaccination and serve as proof of vaccination. Furthermore, countries are asked to maintain these measures until the following criteria have been met: at least six months have passed without new exportations; and documentation of full application of high quality eradication activities in all infected and high-risk areas. In the absence of such documentation these measures should be maintained until at least 12 months have passed without new exportations.