An important staff member of the World Health Organisation (WHO) has warned about a drastic reduction in the global availability of yellow fever vaccines

"Right now our global stock of vaccines has been virtually decimated" said Mike Ryan, coordinator of the Global Outbreak Alert and Response Network of the WHO, during a press conference.

"We are working at our capacity limits regarding massive emergency and prevention campaigns; this is an uncomfortable situation for us", explained Ryan.

WHO depends on three pre-qualified manufacturers for its provision of yellow fever vaccines: Sanofi-Aventis in France, Pasteur Institute in Senegal, and Bio-Manguinhos in Brazil.

According to Ryan, the global production capacity at this moment is somewhere between 30 and 35 million doses.

In recent months WHO has provided vaccines to Paraguay and Brazil in order to control the outbreaks of the mosquito-transmitted illness in these countries. This, however, has reduced their availability for preventive campaigns in some countries of Africa such as Senegal, Togo, Cameroon and Burkina Faso.

Ryan also stressed the importance of keeping adequate stocks of vaccines by means of increasing the present levels of production. The production cost per vaccine is around USD 0.60 each.

"We must keep our vaccine inventories above threshold levels by means of guaranteeing their production in the already existing facilities� said Ryan during the press conference.

Yellow fever is a vector transmitted illness that bares this name due to the fact that one of the major symptoms of infected people is jaundice. The WHO has estimated that 200,000 people are infected every year, and that 30,000 die due to the infection.

In Puerto Iguazú, Argentina, and during the first months of 2007, researchers from Mundo Sano detected the presence of Aedes albopictus, a mosquito vector that is capable of living and spreading yellow fever in urban areas.