Typhoid Vaccine: Complete Guide for Travelers

What Is Typhoid Fever and Why Is Vaccination Important?

Typhoid fever is a life-threatening bacterial infection caused by Salmonella typhi, transmitted through contaminated food and water. It affects approximately 11-21 million people annually and causes 128,000-161,000 deaths worldwide. Vaccination is crucial for travelers to endemic regions where sanitation standards may be inadequate.

Typhoid fever remains one of the most significant infectious disease threats for international travelers, particularly those visiting developing countries in South Asia, Africa, and Latin America. The disease is caused by the bacterium Salmonella enterica serovar Typhi, which spreads through the fecal-oral route when contaminated water or food is consumed. Unlike many travel-related illnesses that cause temporary discomfort, typhoid fever can progress to severe complications including intestinal perforation, sepsis, and death if left untreated.

The World Health Organization (WHO) reports that typhoid fever is particularly prevalent in areas with poor sanitation infrastructure, limited access to clean water, and crowded living conditions. The Indian subcontinent accounts for the highest burden of disease globally, with travelers to India facing the greatest risk among all destinations. However, typhoid occurs throughout Africa, Southeast Asia, Central and South America, and parts of the Middle East.

Vaccination against typhoid fever has been available for over a century, with modern vaccines offering significant protection with minimal side effects. While no vaccine provides 100% protection, typhoid vaccination reduces your risk of infection by 50-80% and typically results in less severe illness if breakthrough infection occurs. This makes vaccination an essential component of pre-travel health preparation, alongside practicing safe food and water hygiene during your trip.

Understanding the Disease Transmission

Typhoid fever spreads exclusively through human carriers - there is no animal reservoir for this disease. Infected individuals shed the bacteria in their feces and, less commonly, in their urine. When sewage contaminates drinking water supplies or when infected food handlers prepare meals without proper hand hygiene, the bacteria can spread to others. Approximately 3-5% of infected individuals become chronic carriers who continue shedding bacteria for years without symptoms.

The incubation period typically ranges from 6-30 days, meaning symptoms may not appear until after you have returned home from your trip. This delayed onset can complicate diagnosis, as healthcare providers in non-endemic countries may not immediately consider typhoid fever. Early symptoms include sustained high fever, headache, malaise, abdominal pain, and either constipation or diarrhea. Without treatment, the disease can progress to serious complications over 2-3 weeks.

Global Burden and High-Risk Regions

The geographic distribution of typhoid fever closely correlates with economic development and water sanitation infrastructure. South Asia, particularly the Indian subcontinent, represents the highest-risk region for travelers. Studies have shown that travelers to India face a typhoid incidence rate approximately 10 times higher than those traveling to other developing regions. Pakistan, Bangladesh, and Nepal also report significant typhoid transmission.

In Africa, typhoid fever is endemic throughout much of the continent, with particularly high rates in East and West Africa. Southeast Asian countries including Indonesia, Philippines, and Vietnam report ongoing transmission, though rates are generally lower than in South Asia. Latin American countries, especially Peru, have documented outbreaks, and sporadic cases occur throughout Central America and the Caribbean.

What Types of Typhoid Vaccines Are Available?

Two main typhoid vaccine types are available for travelers: an injectable polysaccharide vaccine (Typhim Vi) requiring a single dose with protection lasting approximately 3 years, and an oral live-attenuated vaccine (Vivotif) requiring 3 doses over 5 days with protection lasting about 5 years. A newer conjugate vaccine (Typbar-TCV) offers improved protection and can be given to children from 6 months of age.

Understanding the differences between available typhoid vaccines helps you make an informed decision with your healthcare provider about which option best suits your travel needs, timeline, and individual health circumstances. Each vaccine type has distinct advantages and considerations that may influence your choice.

Injectable Polysaccharide Vaccine (Typhim Vi)

The injectable typhoid vaccine, sold under brand names including Typhim Vi, contains purified capsular polysaccharide from the Salmonella typhi bacteria. This inactivated vaccine works by stimulating your immune system to produce antibodies against the bacterial coating, providing protection without any risk of causing the disease itself. The vaccine is administered as a single intramuscular injection, typically in the upper arm.

The polysaccharide vaccine offers several practical advantages for travelers. A single dose provides protection, making it convenient for those with limited time before departure. Protection begins approximately 2 weeks after vaccination, allowing for relatively last-minute travel preparations. The vaccine can be administered from age 2 years, making it suitable for most family travelers. Side effects are generally mild and limited to local reactions at the injection site.

However, the injectable vaccine has some limitations. Protection lasts approximately 3 years, requiring revaccination for frequent travelers or long-term residents in endemic areas. The polysaccharide vaccine does not stimulate T-cell immunity or create immunological memory as effectively as protein-based vaccines, which explains its shorter duration of protection and somewhat lower efficacy in young children.

Oral Live-Attenuated Vaccine (Vivotif)

The oral typhoid vaccine, marketed as Vivotif, contains a live but weakened strain of Salmonella typhi (Ty21a). This vaccine mimics natural infection, stimulating both antibody production and cellular immunity in the intestinal mucosa - the actual site where typhoid bacteria initially invade. The vaccine is taken as a series of enteric-coated capsules over several days.

The standard dosing schedule requires taking one capsule on alternate days (days 1, 3, and 5), totaling 3 doses. Each capsule must be swallowed whole with cold or lukewarm water on an empty stomach, approximately one hour before a meal. The enteric coating protects the live bacteria from stomach acid, allowing them to reach the intestines where they can stimulate immunity. Some countries use a 4-dose schedule.

The oral vaccine provides longer-lasting protection, with studies suggesting efficacy for approximately 5 years. This makes it particularly suitable for frequent travelers or expatriates living in endemic areas. Additionally, some people prefer avoiding injections. The vaccine can be administered from age 6 years in most countries.

Important limitations apply to the oral vaccine. Because it contains live bacteria, it is not suitable for immunocompromised individuals or those taking antibiotics. The multi-dose schedule requires more planning, and the capsules require refrigeration. Protection develops approximately 1 week after completing the full series, so all doses must be finished at least 7 days before potential exposure.

Typhoid Conjugate Vaccines (TCV)

Typhoid conjugate vaccines represent the newest generation of typhoid immunization. These vaccines link the typhoid polysaccharide to a protein carrier, significantly enhancing the immune response and creating longer-lasting protection. The WHO-prequalified conjugate vaccine (Typbar-TCV) has shown efficacy rates of approximately 80% and can be administered to children as young as 6 months of age.

Conjugate vaccines offer several advantages over traditional options. They produce stronger and more durable immune responses, potentially lasting 5 or more years. They are effective in young children who do not respond well to polysaccharide vaccines. They require only a single dose for primary immunization. These vaccines are increasingly being adopted in endemic countries for routine childhood immunization programs.

Availability of conjugate vaccines may be limited in some countries, as they are relatively new to the market. Your travel medicine provider can advise on current availability and whether this option is suitable for your situation.

Who Should Get the Typhoid Vaccine?

Typhoid vaccination is recommended for travelers to endemic regions in South Asia, Africa, Central and South America, and Southeast Asia, particularly those visiting rural areas, staying with local families, or planning extended trips. Laboratory workers who handle Salmonella typhi and people with close contact to typhoid carriers should also be vaccinated.

Travel medicine experts and public health organizations have developed clear guidelines for typhoid vaccination recommendations. The Centers for Disease Control and Prevention (CDC), World Health Organization (WHO), and national health authorities provide similar guidance, emphasizing risk-based decision-making that considers both destination and travel circumstances.

Travelers at High Risk

Certain travel patterns significantly increase typhoid risk and warrant strong vaccination recommendations. Travelers visiting friends and relatives (VFR travelers) face the highest risk, as they often stay in local homes, eat home-prepared food, drink local water, and may have prolonged exposure to endemic conditions. Studies consistently show VFR travelers have higher typhoid rates than other tourist categories.

Adventure travelers, backpackers, and those planning extended stays in endemic countries face elevated risk due to accumulated exposure over time. Travelers to rural or remote areas where healthcare access is limited should be vaccinated regardless of trip duration. Those planning to eat street food, drink local beverages, or stay in basic accommodations have higher exposure risk than luxury hotel guests.

Healthcare workers and humanitarian aid workers in endemic regions should be vaccinated due to potential occupational exposure. Military personnel deployed to endemic regions routinely receive typhoid vaccination as part of pre-deployment health preparation.

Geographic Recommendations

South Asia represents the highest-risk region for travelers. Typhoid vaccination is strongly recommended for all travel to India, Pakistan, Bangladesh, Nepal, and Sri Lanka, regardless of trip duration or travel style. The Indian subcontinent accounts for the majority of travel-associated typhoid cases reported in developed countries.

Africa presents moderate to high risk throughout most of the continent. East Africa (Kenya, Tanzania, Ethiopia, Uganda) and West Africa (Nigeria, Ghana, Senegal) report significant transmission. North Africa (Morocco, Egypt, Tunisia) has lower but still notable risk. South Africa has lower risk but vaccination should be considered for those traveling outside major cities.

Southeast Asia has varying risk levels. Indonesia, Philippines, and Vietnam have moderate risk. Thailand has lower risk but cases occur, particularly in rural areas. Cambodia, Laos, and Myanmar have higher risk profiles.

Central and South America present localized risk. Peru has documented endemic transmission. Mexico, Guatemala, and other Central American countries have sporadic cases. Brazil and other South American countries report occasional outbreaks.

Special Populations

Laboratory personnel who work with Salmonella typhi cultures have occupational exposure risk and should maintain current vaccination. Household contacts of documented typhoid carriers may benefit from vaccination as a precautionary measure. People with anatomic or functional asplenia (absent or non-functioning spleen) have increased susceptibility to severe Salmonella infections and should discuss vaccination with their healthcare provider.

How Does the Typhoid Vaccine Work?

Typhoid vaccines work by exposing your immune system to antigens from Salmonella typhi bacteria, stimulating the production of protective antibodies without causing disease. The injectable vaccine uses purified bacterial coating (polysaccharide) while the oral vaccine uses weakened live bacteria that replicate in the gut to create mucosal immunity.

Understanding how typhoid vaccines generate protection helps explain their efficacy, duration of action, and why multiple vaccine types exist. Each vaccine type stimulates the immune system through different mechanisms, resulting in distinct immunity profiles.

Polysaccharide Vaccine Mechanism

The injectable polysaccharide vaccine (Typhim Vi) works by presenting the Vi (virulence) capsular polysaccharide of Salmonella typhi to your immune system. This polysaccharide forms the outer coating of the bacteria and is a key target for protective immunity. When injected, the polysaccharide antigen is recognized by B cells in your immune system, which then produce antibodies specific to the Vi antigen.

These antibodies circulate in your bloodstream and can recognize and neutralize Salmonella typhi bacteria if you are exposed to the pathogen. The antibodies work by binding to the bacterial surface, marking the bacteria for destruction by other immune cells and preventing the bacteria from attaching to and invading your intestinal cells.

A limitation of polysaccharide vaccines is that they primarily stimulate B-cell responses without engaging T-cells effectively. This results in protection that wanes over approximately 3 years as antibody levels decline. Polysaccharide vaccines also do not generate strong immune memory, which is why booster doses use the same primary vaccination approach rather than simply reactivating prior immunity.

Live-Attenuated Vaccine Mechanism

The oral vaccine (Vivotif) contains Salmonella typhi bacteria that have been genetically modified to be unable to cause disease while retaining the ability to replicate briefly in the gut. When you swallow the capsules, the bacteria are released in your small intestine where they multiply for a short time before being eliminated by your immune system.

This controlled, limited infection closely mimics natural typhoid exposure and generates a comprehensive immune response. Your immune system produces both systemic antibodies (circulating in the blood) and secretory IgA antibodies at the intestinal mucosa - the actual site where typhoid bacteria would normally invade. The vaccine also stimulates cellular immunity involving T-cells, which contributes to longer-lasting protection.

Because the oral vaccine stimulates mucosal immunity, it may provide an additional layer of protection at the initial site of bacterial invasion. This mechanism helps explain why some studies suggest the oral vaccine performs well in field conditions despite laboratory measures of antibody levels that appear similar to the injectable vaccine.

Conjugate Vaccine Mechanism

Conjugate vaccines address a fundamental limitation of polysaccharide vaccines by chemically linking the Vi polysaccharide to a protein carrier. This conjugation transforms the polysaccharide from a T-cell-independent antigen into a T-cell-dependent antigen, fundamentally changing how the immune system responds.

When conjugate vaccines are administered, the protein carrier engages T-helper cells, which then provide signals to B-cells that dramatically enhance antibody production, improve antibody quality, and establish immunological memory. This results in stronger initial antibody responses, longer duration of protection, and more effective responses to booster vaccination.

Crucially, the T-cell-dependent response means conjugate vaccines work effectively in young children, whose immune systems cannot respond well to pure polysaccharide vaccines. This has important public health implications for endemic countries implementing routine childhood typhoid vaccination.

What Are the Side Effects of Typhoid Vaccine?

Typhoid vaccines are generally well-tolerated with mild, short-lived side effects. The injectable vaccine commonly causes pain, redness, and swelling at the injection site (affecting about 1 in 10 people), along with headache, fever, and malaise. The oral vaccine may cause nausea, abdominal discomfort, and diarrhea. Severe allergic reactions are very rare.

Before receiving any vaccination, it is natural to want to understand potential side effects. Typhoid vaccines have been used for decades with an excellent safety record, and serious adverse events are extremely rare. Most people experience either no side effects or only mild, temporary symptoms that resolve within 1-2 days.

Injectable Vaccine Side Effects

The injectable polysaccharide vaccine most commonly causes local reactions at the injection site. Approximately 10-15% of vaccine recipients experience some degree of pain, tenderness, redness, or swelling at the injection site. These local reactions typically appear within hours of vaccination and resolve completely within 48 hours. Applying a cold compress and taking over-the-counter pain relievers can help manage discomfort.

Systemic side effects occur less frequently but may include headache (affecting approximately 5-10% of recipients), fever (3-5%), and general malaise or fatigue (5-10%). These symptoms usually appear within 24 hours and resolve within 1-2 days. Mild muscle aches may also occur. These symptoms indicate that your immune system is responding to the vaccine.

Serious allergic reactions (anaphylaxis) are extremely rare, occurring at a rate estimated at less than 1 in a million doses. For this reason, healthcare providers typically ask you to remain at the clinic for 15-30 minutes after vaccination to monitor for any immediate reactions.

Oral Vaccine Side Effects

The oral vaccine tends to cause gastrointestinal symptoms, which makes sense given that the live-attenuated bacteria replicate briefly in the intestines. Common side effects include nausea (affecting approximately 5% of recipients), abdominal pain or discomfort (3-5%), headache (5%), and mild diarrhea (3%). Fever and skin rash are less common.

Because the oral vaccine contains live bacteria, it theoretically could cause more significant symptoms in immunocompromised individuals, which is why it is contraindicated in this population. In healthy individuals, the attenuated bacteria cannot cause typhoid fever and are quickly eliminated by the immune system.

The oral vaccine requires careful attention to dosing instructions. Taking capsules with hot drinks or shortly after meals may reduce effectiveness by destroying the live bacteria before they reach the intestines. Antibiotics taken around the time of vaccination can also interfere with the vaccine's ability to stimulate immunity.

Conjugate Vaccine Side Effects

Studies of typhoid conjugate vaccines show a similar side effect profile to the injectable polysaccharide vaccine. Injection site reactions (pain, redness, swelling) are the most common adverse events. Fever occurs in approximately 5-10% of recipients, more commonly in young children. Headache, fatigue, and decreased appetite may occur but typically resolve quickly.

The conjugate vaccine has been extensively studied in children in endemic countries, where it has demonstrated an excellent safety profile even when administered to infants. This safety data supports its use in routine childhood immunization programs.

When Should I Get the Typhoid Vaccine Before Travel?

Get the injectable typhoid vaccine at least 2 weeks before travel to allow time for immunity to develop. For the oral vaccine, complete all 3 doses at least 1 week before departure. Ideally, schedule your travel health consultation 4-6 weeks before travel to allow time for all recommended vaccinations.

Timing your typhoid vaccination correctly ensures you have protective immunity before potential exposure. Different vaccine types require different lead times, and your travel timeline may influence which vaccine is most appropriate for your situation.

Injectable Vaccine Timing

The injectable polysaccharide vaccine requires approximately 2 weeks to generate protective immunity. Studies show that antibody levels peak at about 2-3 weeks post-vaccination and then gradually decline over the following years. For optimal protection, receiving the vaccine at least 14 days before arriving in an endemic area is recommended.

If your travel is more imminent, the injectable vaccine can still be administered, with the understanding that protection may not be complete if exposure occurs within the first 2 weeks. Some protection is likely present even at earlier timepoints, and the vaccine may still reduce disease severity if breakthrough infection occurs.

Oral Vaccine Timing

The oral vaccine schedule requires more advance planning. The standard 3-dose regimen is taken on alternate days (days 1, 3, and 5), spanning 5 days. Protection develops approximately 1 week after the final dose. Therefore, you should begin the vaccine series at least 12 days before potential exposure (5 days for dosing plus 7 days for immunity to develop).

Each capsule must be taken on an empty stomach with cool water, approximately one hour before a meal. The capsules must be swallowed whole without chewing. If you miss a dose, you should continue with the remaining doses and complete the series, extending the schedule as needed.

Certain medications can interfere with the oral vaccine. Antibiotics should be avoided from 3 days before the first dose until 7 days after the last dose. Antimalarial medications (specifically mefloquine) should be avoided during the dosing period - this may influence the timing of both your typhoid vaccination and antimalarial medication initiation.

Optimal Planning Timeline

The ideal approach is to schedule a travel health consultation 4-6 weeks before your departure date. This timeframe allows your healthcare provider to assess all your vaccine needs (typhoid is often just one of several travel vaccines recommended), address any contraindications, and ensure all vaccinations have time to generate full protection.

During this consultation, discuss your complete travel itinerary, planned activities, accommodation types, and any special dietary needs or preferences. This information helps your provider give personalized advice about typhoid vaccination and other preventive measures. Be sure to mention any medications you take, as these may affect vaccine recommendations or timing.

How Long Does Typhoid Vaccine Protection Last?

The injectable polysaccharide vaccine provides protection for approximately 3 years, while the oral live-attenuated vaccine protects for about 5 years. Typhoid conjugate vaccines may offer protection for 5 or more years. Frequent travelers to high-risk areas should maintain current vaccination status with appropriate boosters.

Understanding the duration of vaccine protection helps you plan for ongoing travel health needs, particularly if you are a frequent traveler or plan to live in an endemic area long-term. Protection duration varies by vaccine type, and some individual variation exists based on immune response.

Injectable Vaccine Duration

The injectable polysaccharide vaccine provides protective immunity for approximately 2-3 years in most recipients. Antibody levels are highest in the weeks following vaccination and then gradually decline over time. By 3 years post-vaccination, antibody levels in many individuals have fallen below the threshold considered protective.

The WHO and CDC recommend revaccination every 2-3 years for individuals who remain at risk due to ongoing travel or residence in endemic areas. Some guidelines suggest revaccination at 2-year intervals for those with frequent or continuous exposure. Your travel medicine provider can advise on the most appropriate revaccination schedule for your circumstances.

Oral Vaccine Duration

The oral live-attenuated vaccine generates longer-lasting protection, with studies suggesting efficacy for approximately 5 years. The enhanced duration is attributed to the vaccine's ability to stimulate both antibody and cellular immune responses, as well as mucosal immunity in the intestines.

Revaccination with the oral vaccine requires repeating the full 3-dose series. Unlike some vaccines where boosters provide enhanced or more durable protection, revaccination with the oral typhoid vaccine essentially provides a new course of protection. The 5-year interval is considered appropriate for those with ongoing risk.

Conjugate Vaccine Duration

Typhoid conjugate vaccines appear to provide durable protection lasting 5 or more years based on available follow-up data. The enhanced immunogenicity and establishment of immune memory suggest that protection may persist longer than with traditional vaccines. Long-term follow-up studies are ongoing to better define the duration of protection.

Because conjugate vaccines generate immunological memory, booster doses may provide enhanced and more rapid responses compared to primary vaccination. This could allow for simplified booster schedules for frequent travelers, though specific recommendations are still being developed as more data becomes available.

How Effective Is the Typhoid Vaccine?

Typhoid vaccines provide 50-80% protection against typhoid fever depending on the vaccine type and study methodology. The conjugate vaccine shows approximately 80% efficacy in recent trials. Importantly, vaccinated individuals who do experience breakthrough infections typically have milder illness. Vaccination should be combined with food and water precautions for optimal protection.

Vaccine effectiveness data helps set realistic expectations for protection. While typhoid vaccines do not provide 100% protection, they significantly reduce your risk and typically result in less severe disease if breakthrough infection occurs. Understanding these numbers helps you appreciate why additional protective measures remain important.

Clinical Trial Efficacy

Clinical trials of the injectable polysaccharide vaccine have demonstrated efficacy ranging from 55-75% in various populations. Efficacy tends to be higher in adults than in young children, likely due to the nature of polysaccharide immune responses. Protection appears consistent across different geographic regions and populations.

The oral vaccine has shown efficacy of 50-80% in controlled trials, with some variation depending on the number of doses received and population studied. Field effectiveness studies in endemic areas have generally confirmed the vaccine's protective effect, though real-world effectiveness may differ from controlled trial conditions.

Typhoid conjugate vaccines have demonstrated efficacy of approximately 80% in large-scale trials in endemic countries. A landmark trial in Nepal showed 81.6% efficacy against blood-culture-confirmed typhoid fever, representing a significant improvement over traditional vaccines. This enhanced efficacy is particularly valuable for high-risk populations.

Real-World Effectiveness

Real-world vaccine effectiveness may differ from clinical trial efficacy for several reasons. Travelers may have different exposure patterns than endemic populations studied in trials. Storage and handling conditions can affect vaccine potency. Individual immune responses vary. Breakthrough infections may be underreported if they are mild.

Despite these considerations, epidemiological data consistently supports the protective effect of typhoid vaccination in travelers. Studies comparing typhoid rates in vaccinated versus unvaccinated travelers show significant risk reduction. The vaccines also appear to reduce disease severity when breakthrough infections occur.

Why Vaccination Is Not 100% Effective

No vaccine provides complete protection, and several factors contribute to typhoid vaccine limitations. The bacterial inoculum (number of bacteria ingested) affects infection risk - very high doses may overwhelm vaccine-induced immunity. Different Salmonella typhi strains exist, though the Vi antigen is relatively conserved. Individual immune response variations affect protection levels.

Additionally, vaccine protection focuses specifically on Salmonella typhi. The closely related organism Salmonella paratyphi causes paratyphoid fever, which is clinically similar to typhoid but is not prevented by current typhoid vaccines. This is an active area of research, with combination vaccines under development.

Who Should Not Get the Typhoid Vaccine?

The injectable typhoid vaccine is safe for most people with few absolute contraindications. The oral vaccine should not be used by immunocompromised individuals, those taking antibiotics, or children under 6 years. Both vaccines should be avoided by anyone who has had a severe allergic reaction to a previous dose. Pregnant women can receive the injectable vaccine if travel to high-risk areas is necessary.

Understanding who should avoid or use caution with typhoid vaccination helps ensure safe and appropriate vaccine use. Different vaccine types have different contraindication profiles, which may influence your choice if you have specific health conditions.

Injectable Vaccine Contraindications

The injectable polysaccharide vaccine has relatively few contraindications due to its inactivated nature. The primary contraindication is a history of severe allergic reaction (anaphylaxis) to a previous dose of the vaccine or to any component of the vaccine. Moderate or severe acute illness is a precaution - vaccination should be delayed until recovery.

The injectable vaccine can be used in immunocompromised individuals, though immune response may be reduced. Pregnant women can receive the vaccine if travel to a high-risk area is necessary and cannot be postponed - the benefits of protection typically outweigh theoretical risks of an inactivated vaccine. Breastfeeding is not a contraindication.

Individuals with bleeding disorders or those taking anticoagulants should inform their healthcare provider, as intramuscular injection requires modified technique or alternative administration routes. Allergies to latex should be mentioned, as some vaccine packaging may contain latex.

Oral Vaccine Contraindications

The oral live-attenuated vaccine has more extensive contraindications due to its nature as a live bacterial preparation. Immunocompromised individuals should not receive this vaccine, including those with HIV/AIDS (particularly with low CD4 counts), those receiving immunosuppressive therapy, those with congenital immunodeficiencies, and those receiving chemotherapy or radiation therapy.

Concurrent antibiotic use is contraindicated because antibiotics may kill the attenuated vaccine bacteria before they can stimulate immunity. Antibiotics should be avoided from 3 days before the first dose until 7 days after the last dose. This includes oral, injectable, and topical antibiotics that might be absorbed systemically.

The oral vaccine should not be used during acute gastrointestinal illness, as diarrhea or vomiting may impair vaccine absorption and effectiveness. The vaccine is not approved for children under 6 years of age in most countries.

Antimalarial medications require careful timing. Mefloquine specifically should not be taken during the oral vaccine dosing period. Proguanil may also interfere with the vaccine. Atovaquone-proguanil (Malarone), doxycycline, and chloroquine are generally acceptable but should be discussed with your provider.

Special Considerations

Travelers with inflammatory bowel disease (Crohn's disease, ulcerative colitis) or other gastrointestinal conditions should discuss vaccine choice with their provider. The injectable vaccine may be preferred to avoid any potential issues with the oral vaccine in an already compromised gut.

Those who have previously had typhoid fever may already have some natural immunity, but vaccination is still recommended as natural immunity wanes over time and may not be complete. Prior infection is not a contraindication to vaccination.

How Can I Further Protect Myself from Typhoid While Traveling?

In addition to vaccination, protect yourself from typhoid by drinking only bottled or treated water, eating thoroughly cooked foods served hot, avoiding ice and raw vegetables, peeling fruits yourself, and practicing careful hand hygiene. These precautions also protect against other food and waterborne diseases not covered by typhoid vaccination.

Vaccination provides important but incomplete protection against typhoid fever. Combining vaccination with careful food and water precautions significantly reduces your overall risk and protects against many other travel-related illnesses including paratyphoid fever, cholera, hepatitis A, and various causes of travelers' diarrhea.

Safe Drinking Water

Water contamination is a primary route of typhoid transmission. In endemic areas, drink only bottled water from sealed containers, or water that has been boiled for at least 1 minute. Bottled carbonated beverages and hot drinks made with boiled water are generally safe. Avoid tap water, including for brushing teeth.

Ice is often made from tap water and should be avoided unless you know it was made from purified water. Frozen drinks and slushies carry the same risk. If bottled water is unavailable, chemical treatment (iodine or chlorine tablets) or filtration with appropriate pore-size filters can make water safe.

Food Safety

The general principle for safe eating is: "Boil it, cook it, peel it, or forget it." Thoroughly cooked foods served steaming hot are generally safe. Avoid raw or undercooked meat, seafood, and eggs. Be cautious with salads and raw vegetables, as they may have been washed with contaminated water.

Fruits that you peel yourself (bananas, oranges, mangoes) are typically safe. Pre-cut fruit should be avoided. Street food vendors may present higher risk, though freshly cooked items from vendors with visible hygiene practices may be acceptable.

Dairy products should be pasteurized. Avoid unpasteurized milk and cheese in endemic areas. Be cautious with sauces and condiments that may have been sitting at room temperature.

Personal Hygiene

Frequent handwashing with soap significantly reduces infection risk. Wash hands before eating, after using the bathroom, and after touching surfaces in public areas. When soap and water are unavailable, alcohol-based hand sanitizer (at least 60% alcohol) provides an alternative, though it is less effective against some pathogens.

Avoid touching your face, particularly your mouth, with unwashed hands. Carry your own utensils or use disposable options if uncertain about local washing practices.