What to Know About the Typhoid Vaccine

Typhoid fever (simply referred to as typhoid) is not an illness we see all that often in the United States. From a worldwide perspective, however, it is considered a major public health concern with around 21 million new infections and over 150,000 deaths each year.

Even in the United States, as many 5,700 people are believed to be infected annually, according to a report from the Centers for Disease Control and Prevention (CDC). Most are a result of international travel to parts of the world where typhoid is widespread.

The disease, commonly associated with poor hygiene habits and public sanitation conditions, can be prevented with either an oral or injectable vaccine.

How Typhoid Fever Is Transmitted

Typhoid fever is a potentially life-threatening illness caused by the Salmonella typhi bacteria. The bacteria only exists in humans and lives primarily in the bloodstream or intestines.

If a person has typhoid, he or she will shed the bacteria through feces. Any contamination of water, food, or surfaces can facilitate the spread of the disease. Person-to-person transmission, such as through a handshake, is also common.

Within developing regions of the world, the lack of proper sewage systems is a major contributor to widespread infection.

Symptoms

Once infected, the bacteria quickly multiplies and spreads through the bloodstream, causing a range of symptoms across three distinct stages:

• During week one, a person may experience fever, headache, cough, fatigue, slowed heart rate (bradycardia), abdominal pain, and nosebleeds.
• During week two, the exhaustion will have progressed to where the person may not be able to get up. As the fever continues to rise, delirium is common. Rose-colored spots may also develop on the abdomen, while the person may experience either frequent bouts of pea green diarrhea or constipation.
• By week three, the complications can turn severe and may include intestinal hemorrhage, inflammation of the brain (encephalitis), intestinal perforation, inflammation of the heart (myocarditis) and respiratory illnesses such as pneumonia and acute bronchitis.

It is only by the end of week three that the elevated temperatures will begin to subside. Treatment typically involves a course of antibiotics (such as amoxicillin or trimethoprim-sulfamethoxazole) and frequent fluids to prevent dehydration.

If treated in a timely manner, typhoid rarely causes death. However, if left untreated through week three, the risk of death can increase by up to 20 percent.

Typhoid Vaccine Options

Given the consequences of a typhoid infection, persons at high risk can be provided protection with either a single-dose injected vaccine or a four-dose oral vaccine.

There are two vaccines currently approved by the U.S. Food and Drug Administration:

• Typhim Vi is an injectable typhoid vaccine made with an inactivated (fully killed) bacteria which cannot cause disease. It is delivered intramuscularly (typically into the deltoid muscle the upper arm) and only requires a single dose. The vaccine should be given at least two weeks in advance of a trip and can be used in anyone two years and older. Booster shots can be delivered every two years to persons at on-going risk.
• Vivotif is an oral typhoid vaccine made with a live attenuated (live but weakened) bacteria. It is offered in a packet of four capsules, each of which is taken every other day on an empty stomach. Vivotif can be used in anyone six years or older, while booster doses only need to be taken every five years. As a live vaccine, it needs to be refrigerated and should not be given to immune-compromised individuals (such as those with HIV).

Beyond the difference of administration (injection vs. oral) and user restrictions (age and immune status), both vaccines offer around 70% protection from typhoid. This means that you would still need to watch what you eat or drink if ever traveling to a typhoid hotspot.

Side Effects and Contraindications

Side effects are more commonly seen with Typhim Vi with over 10 percent of people experiencing fever, fatigue, headaches, body aches, and injection site pain. With Vivotif, the risk is lower (under seven percent) and may include headaches, nausea, and stomach aches. In both cases, symptoms tend to be mild and resolve on their own without treatment.

On the flip side, there are more drug contraindications with Vivotif than with Typhim Vi. The main concern for both is the drug interactions that can dampen the effect of the vaccine.

In some cases, it is because the drug is an immune suppressant which blocks the production of protective antibodies. These include drugs used to treat autoimmune disorders such as lupus, rheumatoid arthritis, and psoriasis. In some cases, you would need to stop the drug for as long as 30 days before the typhoid shot can be given.

If you need a typhoid vaccination, be sure to advise your doctor of any medications you may be taking and any medical condition associated with immune suppression or a weakened immune system.

When You Need to Vaccinate

According to the Advisory Committee on Vaccinations (ACIP), routine vaccination is not recommended in the United States. There are, however, specific cases when vaccination is strongly advised:

• Travelers to areas where there is a recognized risk of Salmonella typhi
• Persons living with or having intimate contact with someone who has been or is being treated for typhoid fever
• Microbiologists or lab workers who come into contact with Salmonella typhi cultures or specimens

When planning a trip overseas, you can check the current vaccinations requirements and recommendations by visiting the travel health advisory website managed by the CDC.

A Word From Verywell

While typhoid vaccination can significantly reduce your risk of typhoid fever, it’s not fool-proof. In order to ensure you remain safe while traveling abroad, there are 10 common-sense rules you should always follow:

• Wash your hands frequently with soap and hot water.
• Carry an alcohol-based hand sanitizer for times when water isn't available.
• Avoid drinking untreated water.
• While drinking bottled or canned beverages is fine, ask for the drink to be delivered sealed.
• Always ask for drinks without ice.
• Avoid raw fruits and vegetables even if they have been peeled.
• Choose hot foods; foods stored or served at room temperatures should be avoided.
• Avoid street food vendors.
• Use bottled water to brush your teeth.
• Try not to swallow water in the shower.