标题：Preparedness for Infectious Threats: Public–Private Partnership to Develop an Affordable Vaccine for an Emergent Threat: The Trivalent Neisseria meningitidis ACW135 Polysaccharide Vaccine
摘要：With the emergence of epidemic Neisseria meningitidis W135 meningitis in Burkina Faso during early 2002, the public health community was faced with the challenge of providing access to an appropriate and affordable vaccine in time for the upcoming 2003 epidemic season. Recognizing the implications of the emergent threat, the World Health Organization developed a strategy, established a public–private partnership to provide the needed vaccine, and then ensured that a stockpile was available for future use. The trivalent N meningitidis ACW135 polysaccharide vaccine that resulted is now one of the primary tools for epidemic response in African meningitis belt countries. It will remain so for the foreseeable future and until appropriate and affordable conjugate vaccines become part of national immunization programs in the region. DURING 2000 AND 2001, AN unusually high number of Neisseria meningitidis W135 meningitis cases were confirmed among Hajj and Umra pilgrims and their contacts. 1 – 3 This coincided with a high number of N meningitidis W135 meningitis cases being confirmed in Burkina Faso and other African meningitis belt countries (countries located in the semi-arid region of sub-Saharan Africa stretching from Senegal to Ethiopia and subject to seasonal meningitis epidemics between November and June; Figure 1 ▶ ) toward the end of the 2000–2001 epidemic season (October 2000 to June 2001). 4 – 10 In response, the World Health Organization (WHO) and its partners reiterated recommendations for the vaccination of pilgrims and chemoprophylaxis for case contacts and worked to reinforce meningococcal disease surveillance, especially in African meningitis belt countries. Open in a separate window FIGURE 1— Annual meningitis attack rates by country: 1995 to 2003. Source. World Health Organization. 55 In January 2002, the first districtwide meningitis epidemic of the season was detected in Burkina Faso, an African meningitis belt country. By the end of February, 5 epidemic districts had been identified, and reinforced surveillance confirmed an exceptionally high proportion of N meningitidis W135 cases (87%). 11 , 12 The epidemic later spread to 29 of 53 districts, placing more than 7 million persons at risk of disease. During the 2001–2002 epidemic season, a total of 13 735 meningitis cases and 1640 deaths were reported in Burkina Faso with 73% of cases being reported in just 8 weeks during March and April. At the peak of the epidemic, 2172 meningitis cases and 220 deaths were reported to the Ministry of Health in 1 week (week 14; Figure 2 ▶ ). 13 Open in a separate window FIGURE 2— Meningitis surveillance data for weekly reported meningitis cases per 100 000 population from Burkina Faso, Niger, and Mali for 2001–2003. Source. World Health Organization Multi-disease Surveillance Center, Ouagadougou, Burkina Faso, unpublished data, 2004. In Africa, the WHO recommends effective surveillance for the early detection and confirmation of meningitis epidemics linked to a response strategy targeted at reducing mortality (provision of antibiotics) and limiting the emergence of disease (mass vaccination, historically with a bivalent polysaccharide vaccine specific for N meningitidis A and C). 14 , 15 Although sporadic cases of N meningitidis W135 meningitis are common in African meningitis belt countries, 16 – 23 the overwhelming predominance of N meningitidis W135 among confirmed cases together with the magnitude of the 2002 meningitis epidemic in Burkina Faso posed a new challenge to epidemic management in the region.
