Typhoid vaccines. Historical aspects of typhoid vaccine development, and currently available products

Typhoid fever is an acute infectious disease caused by Salmonella enterica subsp. enterica serovar Typhi (S. Typhi), which is still extremely common in endemic low- and middle-income countries of Asia and Africa. Industrialised countries may also be affected by typhoid fever outbreaks due to booming international tourism, and natural disasters. Given S. Typhi progressive resistance to antibiotics, high epidemiological burden, and lack of adequate sanitation and hygiene in a number of regions, the introduction of new treatment protocols and the improvement of preventive vaccination are critical tasks in global healthcare. The aim of the study was to highlight the main historical aspects of the typhoid vaccine development, to summarise data on the licensed vaccines and promising approaches to the development of new typhoid vaccines. The paper describes the current epidemiological situation of typhoid fever globally and in the Russian Federation. It dwells upon the global experience in typhoid vaccine development from the production of an inactivated vaccine to the development of conjugated vaccines. The paper summarises data on Russian and foreign-made typhoid fever vaccines currently available in the global pharmaceutical market. It outlines the main trends in the development of vaccines against the disease caused by S. Typhi. The paper demonstrates the need for improving the efficacy of existing vaccines and development of new typhoid combination vaccines.