30. Cholera vaccines
• Parenteral cholera vaccine not recommended by WHO (low protective efficacy and adverse reaction)
• Two types of safe and effective oral cholera vaccines currently available
Both are whole-cell killed vaccines
Both have sustained protection of over 50% lasting for two years in endemic settings.
Both vaccines are WHO-prequalified and licensed over 60 countries.
Both vaccines are administered in two doses given between seven days and six weeks apart
Recently, however, researchers have suggested that oral cholera vaccines induce “herd immunity”1 1.Ali M, Emch M, von Seidlein L, Yunus M, Sack DA, Rao M, Holmgren J, Clemens JD.Herd immunity conferred by killed oral cholera vaccines in Bangladesh: areanalysis.Lancet. 2005 Jul 2-8;366(9479):44-9