Ty21a

From Wikipedia, the free encyclopedia

Ty21a is a vaccine that protects against typhoid. It is one of two vaccine currently recommended by the World Health Organization.^[1] The vaccine offers between 33 and 78% protection. The vaccine is most commonly used to protect travellers to endemic countries, but there is no reason why the vaccine could not be used in large scale public prevention programmes.^[1]

The vaccine is given by mouth. The vaccine is presented either as capsules or a liquid suspension. The vaccine must be stored at 2 to 8°C, but will retain its potency at for 14 days at 25°C.^[1]

[edit] Dosing

The recommended dose varies according to country.

In the US and Canada, an initial course of 4 doses on alternate days is recommended. Protection is achieved 7 days after the last dose. In the US, a booster dose is recommended after 5 years. In Canada, a booster dose is recommended after 7 years.

In Australia and Europe, and initial course of 3 doses on alternate days is recommended. Protection is achieved 7 days after the last dose. A booster is recommended every 3 years for people living in endemic areas, but every year for people travelling from non-endemic to endemic areas.

[edit] References