Vi capsular polysaccharide vaccine
Encyclopedia
The Vi capsular polysaccharide vaccine (or ViCPS) is one of two vaccines recommended by the World Health Organisation for the prevention of typhoid (the other is Ty21a
). It was first licensed in the US in 1994 and is made from the purified Vi capsular polysaccharide from the Ty2 Salmonella Typhi strain; it is a subunit vaccine.
The vaccine is only 50 to 80% protective and the traveller should still be warned to take all usual precautions (careful hygiene, hand washing and food preparation).
recommend 14 days). The vaccine is not effective in children under the age of two; children under the age of two would normally have all their food regulated by their parents and should therefore be expected to be at low risk of exposure to typhoid.
To maintain immunity, the vaccine should be repeated every three years.
Ty21a
Ty21a is a live attenuated bacterial vaccine that protects against typhoid. It is one of two typhoid vaccines currently recommended by the World Health Organization. The vaccine offers a statistically significant protection for the first three years, with between 8% to 54% effectiveness for the...
). It was first licensed in the US in 1994 and is made from the purified Vi capsular polysaccharide from the Ty2 Salmonella Typhi strain; it is a subunit vaccine.
The vaccine is only 50 to 80% protective and the traveller should still be warned to take all usual precautions (careful hygiene, hand washing and food preparation).
Indications
The vaccine may be used in endemic areas in order to prevent typhoid. It is also commonly used to protect people who are traveling to parts of the world where typhoid is endemic.Dosing
The vaccine is injected either under the skin or into a muscle at least seven days before traveling to the typhoid-affected area (the CDCCenters for Disease Control and Prevention
The Centers for Disease Control and Prevention are a United States federal agency under the Department of Health and Human Services headquartered in Druid Hills, unincorporated DeKalb County, Georgia, in Greater Atlanta...
recommend 14 days). The vaccine is not effective in children under the age of two; children under the age of two would normally have all their food regulated by their parents and should therefore be expected to be at low risk of exposure to typhoid.
To maintain immunity, the vaccine should be repeated every three years.
Efficacy and duration of protection
The vaccine offers effective protection the first year after being given (with between 50% to 80% efficacy) and the second year (31% to 76%), but not after that.Trade names
- Typhim Vi (manufactured by Sanofi PasteurSanofi pasteurSanofi Pasteur is the vaccines division of sanofi-aventis Group. It is the largest company in the world devoted entirely to vaccines.- History :...
) - Typherix (manufactured by GlaxoSmithKlineGlaxoSmithKlineGlaxoSmithKline plc is a global pharmaceutical, biologics, vaccines and consumer healthcare company headquartered in London, United Kingdom...
)