Meeting the public health challenge of epidemic meningitis in Africa
The right vaccine to the right people at the right time
The epidemics of meningitis in 1996-97 in Africa killed more than 20,000 people. In response, WHO and its partners, UNICEF, Médecins sans Frontières, and the International Federation of Red Cross and Red Crescent Societies, were determined that the limited amount of meningitis vaccine then available would be used where it was needed most. The International Coordinating Group (ICG) for Vaccine Provision for Epidemic Meningitis Control was born soon after: a stock of needed vaccine was set up for rapid distribution during an epidemic to countries in the African meningitis belt - an area stretching from Senegal to Ethiopia where some 300 million people live. In the last 10 years, with over 700,000 people suffering from the disease and 100,000 people dying, the ICG has continued to provide rapid access to meningitis vaccine as well as to injection materials and drugs. Thanks to Aventis-Pasteur who have made vaccine stocks available at low prices , the ICG has been able to distribute 20 million doses of vaccine against the A and C strains, the strains responsible for the majority of epidemics in Africa.
In 2002, a new strain of the disease, W135, struck more than 13,000 people in Burkina Faso and killed at least 1500. Recognizing the urgent need for a vaccine that could protect against this new strain as well as the other common strains in Africa, GlaxoSmithKline collaborated with WHO. A new vaccine to fight against A, C, and W135 was produced and licensed in record time.
Getting ready in countries
Two million doses of affordable vaccine were effectively used in Burkina Faso in 2003 to control another W135 outbreak. With an unprecedented level of support from ICG partners and the international community, a stockpile of 6 million doses of the new vaccine is now established. As a result of this effort, vaccine was readily available to control a W135 outbreak in Burkina Faso in 2004. Safe, effective vaccine to fight a meningitis epidemic is now a reality but more needed to be done to prevent a meningitis epidemic from developing in the first place.
The emergence of W135 made it even more critical for countries to detect the disease early, identify the strain correctly and respond quickly with the appropriate vaccine. Their task is to contain and localize an outbreak before it spreads throughout the country and perhaps across borders to its neighbours. Different parts of WHO came together to meet this challenge: the alert and response group and the group working to strengthen disease surveillance and laboratory capacity in headquarters, the Regional Office for Africa and a newly-created meningitis team based in Ouagadougou, Burkina Faso. Funds are provided for this team by the Meningitis Vaccine Project (MVP) a partnership between PATH and WHO. Using a specially developed software, the team reviews the epidemiological data, with special emphasis on detecting alerts for potential epidemics. Reporting data is standardized using a common case definition, common indicators for assessing the size of the outbreak and the data mapped with the help of WHO's HealthMapper.
Ten countries in the African meningitis belt have developed and implemented standard operating procedures for enhancing surveillance. Data now moves quickly and consistently from district to national level and guidelines for collecting specimen samples have been put in place. The team provides training in organizing, recording and analysing data, produces a weekly epidemiological bulletin shared among the countries and monitors the implementation of these operating procedures to ensure that best practices are followed.
A brighter future
At the same time, supplies of vaccine, reagents for testing and transport media for collecting samples are pre-positioned in the 10 countries. Standardized laboratory protocols have been developed to ensure rapid diagnosis of the strain so that the correct vaccine is used. WHO's work in quality assured laboratory capacity is also key in improving laboratory surveillance. To ensure that the vaccine is used appropriately, a group of technical experts has developed criteria for the use of both bivalent and trivalent vaccines.
Africa was spared a major meningitis epidemic in 2004, but this season's outbreaks still claimed more than 12,000 cases and 2000 deaths. There was, though, a difference from the past - the countries of the African meningitis belt were better armed and ready to meet the disease head on: responses were quicker and control measures were better targeted, resulting in a decrease in the disease burden in affected districts. Precious supplies were used effectively and appropriately. But there is more work ahead.
All the meningitis polysaccharide vaccines available today do not provide long-lasting protection, so vaccination needs to be repeated for at least 80% of the population each time an epidemic occurs. They cannot be given to children younger than 2 years of age and the vaccine has no effect on the trans-mission of the disease within populations, so people who carry the disease but do not show any symptoms can transmit the infection to close contacts.
The MVP is working to develop a conjugate vaccine which will not have these limitations. Recently, the Serum Institute of India Ltd. joined the effort to develop a conjugate meningitis A vaccine at a cost of 40 cents per dose, which is scheduled for 2009. This research promises to be a great step forward towards making these vaccines cheaper and more accessible for the people of sub-Saharan Africa. Until then, WHO's work in countries and with partners will continue to raise the alert early and respond to meningitis epidemics wherever and whenever they occur.