Which shots to get

When it comes to immunizations, travelers may have a world of misconceptions.

“It’s too late (or too early) to get the vaccines I need,” they think, or “I got all my shots in childhood.”

Figuring out which immunizations one needs for a trip abroad isn’t simple, travel medicine physicians note. It depends on several factors, including the traveler’s health, previous vaccines, the destination and where the traveler plans to stay and visit.

A person traveling in rural areas of a developing country, for instance, probably needs protection different from a traveler who stays in the city at a luxury hotel with little interaction with the locals, said Dr. Brian Terry, a Pasadena physician specializing in travel medicine.

It’s best to check months before departure, but certain vaccines — hepatitis A, polio booster, tetanus booster — can be given practically “on the way to the airport,” Terry said. Ideally, they should be given well before that, of course, but in a worst-case scenario, some protection is better than none.

As a starting point, travelers can turn to the federal Centers for Disease Control and Prevention, https://www.cdc.gov/travel, and research immunizations needed by their destination.

Checking the Outbreaks section, which lists diseases by their occurrence in a region, is also advised.

The World Health Organization’s site, https://www.who.int, allows travelers to access a country-by-country list or a listing by specific disease to learn about immunization requirements.

To find a travel medicine specialist, check the International Society of Travel Medicine website, https://www.istm.org, which maintains a listing of more than 500 travel medicine clinics in more than 40 countries.

Once a traveler arrives at a travel medicine clinic, physicians there usually access specialized databases that draw on information from the CDC, WHO and other sources to determine which immunizations are needed.

Among the most commonly recommended vaccines, depending on destination and other factors:

Yellow fever: The mosquito-borne viral disease occurs in sub-Saharan Africa and tropical South America; illness ranges in severity from a flu-like cold to severe hepatitis and hemorrhagic fevers, a group of illnesses that affects multiple organ systems.

Hepatitis A: This viral infection of the liver can be mild or last several months. Transmission can occur through contaminated water, ice or food or from person-to-person contact. The risk increases in areas of poor sanitation, although many cases have been reported by travelers in developing countries who participate in “standard” tourist itineraries and accommodations, according to the CDC.

Influenza: Flu may rank with hepatitis A as one of the “vaccine-preventable” diseases for travelers, the CDC said.

Typhoid fever: The CDC recommends the vaccine for this acute fever illness for those going to the Indian subcontinent and low-income countries in Asia, Africa and Central and South America, if they will have prolonged exposure to potentially contaminated food and drink.

Depending on destination, your doctor also may also recommend a booster for polio or tetanus.

Travelers often don’t think about the rabies vaccine, probably because deaths from that disease are rare in the United States. But the disease is prevalent in several countries, including Mexico, Peru and Vietnam, the CDC said.

Pre-exposure vaccine may be recommended, especially if travelers plan to bike or camp and will be more likely to be exposed. This precaution doesn’t eliminate the need for medical attention after rabies exposure, but the pre-exposure vaccine does decrease the number of doses needed after a bite.

Procrastinators will be happy to know that multiple vaccines given at once are safe, according to research published last year in the Journal of Travel Medicine. Researchers evaluated 1,035 travelers who were immunized against such diseases as yellow fever, hepatitis A, typhoid and tetanus. Those who got two or three shots at once tolerated them fairly well, the research found. But they noted that those with autoimmune disorders, such as lupus or Graves’ disease, should avoid multiple shots because they might trigger flare-ups.Procrastinators will be happy to know that multiple vaccines given at once are safe, according to research published last year in the Journal of Travel Medicine.