Vaccination Week events from April 24-30, coordinated by Pan American Health Organization (PAHO), the regional arm of WHO, are targeting some 40 million people. In Haiti, 79,000 children five years old and under are the focus of an immunization campaign against polio.

A Red Cross volunteer calls out to residents of Lascahobas informing them of the vaccination campaign. Through its volunteers, the Haitian Red Cross has been supporting the Ministry of Health in a week long social mobilization campaign prior to Vaccination Week and National Immunization Days (NID).

Two Haitian Red Cross volunteers administer the oral polio vaccine (OPV). A total of 150 Haitian Red Cross volunteers are taking part in the campaign across the country. The International Federation of Red Cross and Red Crescent Societies has contributed to this campaign through financial support of the Haitian Red Cross.

A child wears a sticker saying "I am vaccinated" in Creole. She has just been immunized. In this simple way she is one step closer to being free of polio.

A Chad Red Cross volunteer encourages the residents of Tréguine to wait in line for the medical team.

The refugee children in Tréguine are among 80 million children in sub-Saharan Africa being immunised against polio.

Children under five cannot touch the opposite ear with their arm stretched over their head: a quick way to confirm that the child is within the target age group. Children over five are less at risk from polio and do not require vaccination.

Most children willingly submit to the perplexing experience thanks to the time spent explaining the process to mothers and traditional leaders.