Typhoid Conjugate Vaccine Trial Among Children Younger Than 2 Years in Ouagadougou, Burkina Faso

Typhoid fever is an illness that may cause mild effects in children, such as fever and feeling tired, or it may cause serious effects-- even death. A new typhoid vaccine has recently been recommended by the World Health Organization (WHO) to prevent typhoid in children. But this new typhoid vaccine has not been tested with all of the vaccines given to children in Burkina Faso. The investigators want to look at this new vaccine, and study how safe it is in children in Burkina Faso and how their immune systems respond to the vaccine when given with other vaccines, such as yellow fever and meningitis A vaccines. The investigators plan to vaccinate 100 children between the ages of 9-11 months, and 150 children between the ages of 15 months and 2 years, in Ouagadougou, Burkina Faso, with either the typhoid vaccine or a vaccine against another illness called polio. Children will have follow-up visits on days 3, 7, 28 and 180. One teaspoon of blood will be collected on days 0 and 28.