Typhoid Vaccine

Typhoid vaccine is a vaccine used against typhoid fever.

There are two effective types:

• Ty21a, which is a live vaccine given orally
• Vi capsular polysaccharide vaccine, which is an injectable subunit vaccine

Ty21a is licensed for use from age six years and older. Boosters are recommended annually. The Vi capsular polysaccharide vaccine is licensed for use from age two years and older, and boosters are required every three years.

Almroth Edward Wright developed an effective inactivated whole-cell typhoid vaccine that was introduced in 1896. Due to side-effects its usage was eventually discontinued.

An experimental vaccine called Vi-rEPA has showed promising results in trials so far, indicating higher effectiveness and longer immunity. However, it has yet to be licensed for use.