The typhoid shot (injectable vaccine) is good for 2 years. After that, you need a booster dose if you’re still at risk. The oral typhoid vaccine lasts longer, at 5 years before a booster is needed. Which type you received determines your revaccination timeline.
Injectable vs. Oral Vaccine Duration
Two typhoid vaccines are licensed in the United States, and they have different protection windows:
- Injectable vaccine (Typhim Vi): One shot, good for 2 years. A booster is recommended every 2 years for people who remain at risk.
- Oral vaccine (Vivotif): A series of 4 capsules taken every other day, good for 5 years. The full four-capsule series is repeated as the booster.
These timelines come from the CDC’s Yellow Book guidelines for travel medicine. Neither vaccine provides lifelong immunity, so if you travel repeatedly to areas where typhoid is common, you’ll need to keep up with boosters on the appropriate schedule.
How Effective Are These Vaccines?
Neither vaccine is a guarantee against typhoid. The injectable shot prevents roughly 58% of infections, based on pooled data from clinical trials. The oral vaccine is slightly less effective, preventing about 43 to 45% of cases over the first few years. These numbers mean the vaccines meaningfully lower your risk, but safe food and water habits still matter when you’re traveling.
A newer option called the typhoid conjugate vaccine (TCV) performs significantly better, with about 79 to 88% efficacy in studies following participants for up to two years. The WHO now prefers TCV for routine use because it works in younger children (starting at 6 months) and is expected to provide longer-lasting protection. TCV is widely used in typhoid-endemic countries but is not yet licensed in the United States.
Timing Before Travel
If you’re getting the injectable vaccine, you need it at least 2 weeks before your departure to give your immune system time to build protection. The oral vaccine requires more planning. You take one capsule every other day for a total of four capsules, and the last dose should be taken at least 1 week before travel. That means you need to start the oral series about 2 weeks out as well.
If your trip is less than two weeks away and you haven’t been vaccinated, the shot is the more practical option since it only requires a single visit.
Who Needs a Typhoid Vaccine
Typhoid vaccination is recommended for travelers heading to parts of South Asia, Southeast Asia, Africa, and Latin America where the disease is common. It’s also recommended for people who have close contact with a known typhoid carrier or who work in labs handling the bacteria. The injectable vaccine can be given to anyone age 2 and older. The oral vaccine has a higher age cutoff, requiring the recipient to be at least 6 years old.
Keeping the Oral Vaccine Effective
The oral typhoid capsules contain a live, weakened form of the bacteria, and they’re sensitive to temperature. The capsules must stay refrigerated between 35.6°F and 46.4°F (2°C to 8°C) at all times. If you pick up the prescription from a pharmacy, get it into your refrigerator quickly and put unused capsules back between doses. Capsules stored at room temperature lose potency, which could leave you unprotected even if you complete the full series.
You should also avoid taking antibiotics while completing the oral series, as they can kill the weakened vaccine bacteria before your immune system has a chance to respond.
When Your Booster Is Overdue
If more than 2 years have passed since your typhoid shot (or more than 5 years since your oral series) and you’re planning another trip, you’re no longer considered protected. The booster process is straightforward: one new injection for the shot, or a repeat of the full four-capsule oral series. There’s no need to “start over” with additional doses for the injectable version since a single booster shot restores protection.
If you can’t remember exactly when you were vaccinated, your doctor’s office or the travel clinic where you received it should have records. Some people keep this information on a vaccine card alongside other travel immunizations like yellow fever, which can simplify things for future trips.