Polio Eradication Initiative | Strategy/policy | Supplementary immunization

Supplementary immunization

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Vaccinators trying to cross a canal to reach childrenVaccinators try to vaccinate children in difficult to reach areasPolio campaigns are known as national immunizations days when they cover an entire country, and subnational when they only cover part of a country. These polio campaigns aim to interrupt transmission of wild polioviruses by immunizing all children under 5 years of age at the same time, regardless of previous immunization status. As a result, the wild virus will be unable to survive.

When more than one round is planned, a space of one month between doses is essential, except if the vaccine used in the two consecutive rounds is monovalent of the same type. In this case, the period can be much shorter.

Since 2006, supplementary immunization activities have been implemented using either trivalent oral polio vaccine (tOPV), monovalent oral polio vaccine type 1 or 3 (mOPV1 or mOPV3), or bivalent vaccine (1+3). The type of vaccine used depends on the epidemiologic situation.

In areas with limited accessibility the short interval additional dose strategy has been adopted, in which the second dose is given after a shorter period than one month, possibly even as short as one week.

Targets and percentage coverage by supplementary immunization activity in the Eastern Mediterranean Region by year.

Indicators and information

Wild polio cases by country in the Region for 2017–2018


P1 Total



14 14


8 8

Total 2017

22 22



21 21


12 12

Total 2018

33 33



2 2


4 4

Total 2019 (up to 17 March 2019)

6 6

Polio Fax issues

Middle East Polio Technical Bulletin

Surveillance Indicators

Supplementary Immunization Activities

Routine immunization
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