"This campaign comes at a critical time while the country is witnessing a huge internal exodus of children fleeing violence and turmoil," said Marzio Babille, Unicef Iraq representative, in a press release.
"This is a top priority for Unicef. No child should be missed. No child should be paralysed."
The on-going violence in Iraq has precipitated the internal displacement of nearly 1.2 million people since the beginning of the year. Almost 200,000 have been displaced in the last three days alone in the Kurdistan Region.
Unicef estimates half of that number are children.
"As the violence spreads, children are being displaced up to three times with their families, often living in overcrowded conditions where they are at a much higher risk of contracting infectious diseases," said Syed Jaffar Hussain, the WHO's Iraq representative.
With two cases of polio being detected in Iraq after the country became polio-free for 14 years and a relatively high number of unvaccinated children due to difficulties in accessing families and children, especially in conflict zones and due to social reservations, Iraq has now become vulnerable to a wider outbreak of the vaccine-preventable crippling disease, Unicef said.