This shortfall in numbers, but not in coverage, allows MSF to explain some of the issues and complications inherent in trying to offer basic, essential medical care in many of the coutries where we work. 
For 12 consecutive days, more than 500 people have worked together to complete the vaccination campaign in Mbuji Mayi, in the Kasai Oriental Province (DRC). The MSF team consisted of 10 expatriates and a few logisticians from MSF's emergency pool in DRC working with local health structures' staff.

The target population was all children aged between six months and five years in Mbuji Mayi, a city that has an estimated population of 2.5 million people, with up to 550,000 being children in the target range.

In Africa, estimating target populations relies on calculating percentages of the total population - and the percentage used changes according to additional information specific to the region. The campaign itself is a massive mobilisattion of staff and equipment - and the cooperation of hundreds of thousands of people throughout the region.

But this shortfall allows MSF to explain some of the issues and complications inherent in trying to offer basic, essential medical care in many of the coutries where we work.

"Populations in Africa are not easy to estimate," explained Anne Decoster, coordinator of the mission. "In some cases, when we need to vaccinate children between 6 and 59 months, we calculate our target group by estimating that it represents 17, 18 and sometimes 15 per cent of the global population.

"In this case, MSF used figures provided by the local representation of the EPI (Extended Programme of Immunisation), which estimates that, in Mbuji Mayi, 16% of the population is aged between 6 months and 5 years. Ã? The city's censuses thus indicate that there are 368,282 children.

"After the planned 12 days of vaccination; we had vaccinated 359,318 children. This means we have reached more than 97% of the target population. Those results are based on the number of doses actually administered to children. In order to evaluate with more precision the success of the campaign, a survey among the population is currently being undertaken."

In each of the 10 health zones of the Kasai Oriental's capital, four days of vaccination were organised. More than 100 vaccination sites were installed where one or two teams vaccinated thousands of children. The campaign was divided into three phases: the first one targeted the zones of Nazba, Bipemba and Mopkolo, the second focused on Diulu, Muya and Kansele, and the last one covered Bonzola, Lukelenge, Lubilanji and Dibindi.

In these areas are hundreds of thousands of people who have walked through the successive steps of the vaccination line: first the person who hands the vaccination cards, then the two who prepare the vaccine, the vaccinator and finally the person who fills in the tally sheets to keep track of the number of vaccinated children. There were also agents recruited to keep the order in case of high flux of people. Teams also worked across the zones to sensitise people through megaphones repeating the same message about a free vaccination campaign against a deadly disease.

The logistical set up for this campaign required a lot of work, especially in terms of equipment and vaccines transport to the different sites, often only accessible by motorcycle. About 60 of them and 10 more vehicles were used during the campaign.

"Now that the campaign is over we need to take inventory of the remaining stock" says Ann Decoster. "The remaining vaccine doses initially given by the Kinshasa EPI will now be left with the Mbuji Mayi EPI. Also, free treatment of measles cases continues to be provided in 4 health centres and hospitals. This will probably end at the end of April".

A doctor and a nurse from the MSF's emergency pool in DRC will remain for that purpose. Expatriates are starting to head back home. Two logisticians have left Mbuji Mayi already, and a part of the team will follow them. Some will stay to follow up the treatment effort and others to be involved in the epidemiological survey which should, in a few weeks time, provide an analysis of the outbreak and the impact of the vaccination campaign.