Vaccination campaigns are core part of Médecins Sans Frontières (MSF) activities in many countries. Although in the developed world measles has been almost overcome, in many countries it remains a major public health concern. The high mortality rate due to measles is preventable and mass immunisation against measles is one of the top priorities in an epidemic. Measles is an highly contagious viral infection which is easy to prevent, thanks to a cheap and efficient vaccine.

The infection can lead to severe complications such as pneumonia, diarrhoea, malnutrition, skin lesions, conjunctivitis and vitamin A deficiency resulting eventually in blindness. Malnutrition leads to a lower immune response making a person more prone to infectious diseases like measles. In turn, measles patients are more likely to become malnourished as a consequence of their infection. Children under one year of age have the highest case fatality rate; in epidemic situations as many as one in five infected children may die.

"Since January 2008, an increasing number of measles cases have been reported in the administrative zone of Guji, in Oromyia, the largest region of Ethiopia," said Francois Calas, MSF Head of Mission in Ethiopia. "We decided to send a medical team to the area in order to assess the needs. Measles cases were clinically confirmed in five districts, therefore we decided to do a mass vaccination campaign.

This campaign should last two weeks, and cover the two most affected districts. We aim at immunising around 100,000 children between six months and 15 years old." In Oromiya, MSF is now carrying out one of the biggest vaccination campaigns done by the medical organisation in recent months. In this part of Ethiopia, access to health care is poor, the area lacks infrastructure, medical personal and drugs.

The two districts where MSF intervenes are densely populated which promotes the transmission of measles. In these districts, MSF focuses its efforts on immunisation, treatment of patients and epidemiological surveillance. "The first day of our work in Hambella village, we treated 92 children who had measles," said Calas. "Two children suffered from severe pneumonia; we treated them and they are now improving, thanks to antibiotics.

"We also found three malnourished children who are now slowly gaining weight. These are just some of the complications that we see in children affected by measles, complications that make it difficult for them to regain their health or survive." At the moment eight international MSF staff are working in the vaccination campaign in Oromyia, together with 150 Ethiopian MSF staff.