Development of Vi conjugate – a new generation of typhoid vaccine

摘要: Typhoid fever remains to be a serious disease burden worldwide with an estimated annual incidence about 20 million. The licensed vaccines showed moderate protections and have multiple deficiencies. Most important of all, none the typhoid demonstrated protection for children under 5 years old. These limitations impeded successful implementation vaccination programs. To improve immunogenicity Vi was conjugated rEPA, recombinant exoprotein A from Pseudomonas aeruginosa. Vi-rEPA higher longer lasting anti-Vi IgG in adults than alone high endemic areas. In school-age adults, immunity persisted more 8 years. double-blind, placebo-controlled randomized efficacy trial 2- 5-year-old children, conferred 89% protective against lasted at least 4 When given concomitantly infant routine vaccines, safe, immunogenic no interference vaccines. conjugate vaccine also attempted successfully by several other laboratories manufactures. Using either rEPA or different carrier proteins, such as diphtheria tetanus toxoid, toxin (CRM197), conjugates synthesized significantly alone. Recently, two Vi-tetanus toxoid were India all ages, starts young 3 month This new generation opens up era prevention elimination.