The typhoid vaccine name refers to two approved vaccines: Ty21a (oral) and Typhim Vi (injectable). These protect against typhoid fever caused by Salmonella Typhi bacteria.
Both vaccines train your immune system to recognize and fight Salmonella Typhi. The oral vaccine uses weakened bacteria, while the injectable contains purified capsular polysaccharides. Neither provides 100% protection, but both reduce risk.
| Vaccine Name | Type | Age Range | Protection Duration |
|---|---|---|---|
| Ty21a | Oral | 6 years and older | 5-7 years |
| Typhim Vi | Injectable | 2 years and older | 2-3 years |
Travelers to endemic areas (South Asia, Africa, parts of Latin America) should consider vaccination. The CDC recommends it for those visiting friends/relatives abroad, as they're at higher risk due to local food/water consumption.
Many confuse typhoid vaccines with those for cholera or paratyphoid. While related, these require separate vaccinations. The typhoid vi polysaccharide vaccine is often mistaken for a newer formulation, but it's been in use since the 1990s.
During my trip to India, I received the injectable Typhim Vi vaccine. The clinic recommended it over the oral version due to my tight schedule (oral requires multiple doses spaced days apart). Protection lasted through my entire 3-week stay.