Development of Glyco-Conjugate Vaccines for Prevention of Salmonella Related Diseases in Africa

Incidence of Salmonella related diseases in many parts of sub-Saharan Africa is still largely unknown due significant lack of diagnostic capacity. However, recent publications show high incidence of typhoid fever and non typhoid salmonella (NTS) infections in various African countries; this is particularly true in children below five years of age. For NTS, predominantly caused by S. Enteritidis and S. Typhimurium, available data support the epidemiological relevance of the disease with an estimated 1 million yearly cases and approximately 100.000 deaths, with a peak in the first two years of life, in Africa.  These infectious diseases could be prevented using vaccines that unfortunately are not yet available for lack of commercial incentives to invest in the field of diseases primarily affecting developing countries. To fill this gap, the Novartis Vaccines Institute for Global Health (NVGH) was created in 2008 with the not for profit mission of developing effective and affordable vaccines against diseases affecting the most impoverished populations. Key to the potential success of NVGH, compared to other institutions with the mission to change the global health scenario in low income countries, is its access to know-how and technologies of a major vaccine manufacturer, which allows NVGH to be a reliable player for the development of new vaccines. NVGH focus in vaccine development is on diarrheal diseases including a series of new vaccines against Salmonella related diseases. Among them conjugate vaccines against S. Typhi, S. Paratyphi A and Non Typhoidal Salmonella. The first of these vaccines, obtained by conjugation of the Vi polysaccharide, major virulence factor of S. Typhi, with the carrier protein CRM197, has been already evaluated in Phase 2 clinical trials in endemic countries while the NTS vaccine is ready to start clinical development.