Working Group on quality, safety and efficacy of typhoid Vi capsular polysaccharide conjugate, vaccines, Jeju, Republic of Korea, 5-7 September 2012.

Typhoid fever is a gastrointestinal disease transmitted through the ingestion of contaminated water or food. The bacterium, Salmonella enterica subspecies enterica serovar Typhi is an important cause of illness and death in many poor countries where access to safe water and basic sanitation is limited. Humans are the only natural host and reservoir of S. Typhi. Typhoid fever causes around 21 million cases and at least 200,000 deaths per year. Currently, several groups are developing typhoid conjugate vaccines that are expected to be safe and effective in infancy or early childhood. The World Health Organization convened a meeting, in collaboration with the Korea Food and Drug Administration, with experts group in September 2012 to develop guidelines for regulatory evaluation of the quality, safety and efficacy of typhoid conjugate vaccines. This report summarizes collective views on scientific and technical issues that need to be considered in the guidelines.