The immunization of children in America is a controversial subject for parents and medical professionals alike. Many of the diseases routinely vaccinated for in the U.S. are either mostly eradicated domestically or non-lethal, and because there is some evidence that immunizing young children may compromise their immune system, a growing number of American parents now choose to avoid vaccinating whenever possible. For the kids who grow up entirely within America’s relatively sanitary and medically advanced borders, this decision probably results in stronger healthier bodies more often than not, but for those children whose parents are given to traveling abroad, the issue is considerably more complex.

“It is important to immunize children when traveling for the same reasons that it is important to immunize adults -- because they will likely be exposed to malicious entities against which their bodies have no natural defense -- with the significant added factor that many diseases are more severe in younger children,” says Dr. Edward K. Chapnick, M.D., Director of the Infectious Diseases Division at Maimonides Medical Center in Brooklyn, NY. “Most children born and raised in the United States, are not likely to possess a natural immunity to the diseases commonly endemic in developing countries, and immunity can wane even for children who were initially raised in foreign countries after they come to an area where exposure is unlikely.”

“Our daughter is very important to us and we don't want to take any unnecessary risks by not vaccinating her before we travel, but we also want her to have a naturally healthy immune system so we will avoid vaccinating her if it is not absolutely necessary,” says Rachelle Canady, from Ashland, Ore., who intends to spend the next year traveling in New Zealand and Central America with her 2-month-old daughter, Amani, and her partner Lorin Mussell. “Ultimately our goal is to get only the most necessary of the vaccines and wait as long as possible before vaccinating her in order to enable Amani's body to be stronger and more equipped to deal with them.”

Dr. Chapnick explains that, though infants under 2 weeks of age should not undertake air travel, there are no areas in the world where parents can’t take their children. One of the primary limiting factors is the minimum age at which a child can adequately respond to the vaccines necessary for a particular region.

Dr. Chapnick recommends that children be up to date, or accelerated, on all standard immunizations prior to international travel, with additional immunizations considered on a case-by-case basis, depending on the age of the child and the parent’s intended destinations.

“Vaccine efficacy is dependent on the type of immunization,” Dr. Chapnick says. “For example, oral typhoid vaccine is practical only for children age 6 years and over, but the injectable version can be effective as early as 6 months. The yellow fever vaccine on the other hand, a requirement for travel in some countries in South America and eastern Europe, is only effective in children over 9 months of age.”

Ideally, vaccinations should be given by the child's pediatrician and/or by a travel medicine facility at least four weeks prior to travel but, according to Dr. Chapnick, “in an urgent situation, two weeks is probably adequate for the vaccine to take effect.”

The Center for Disease Control suggests that the following immunizations normally given during childhood should be up to date for children over 2 years of age before traveling internationally:

• Measles, Mumps, and Rubella (MMR)
• Diphtheria, Tetanus, and Acellular Pertussis (DTaP)
• Polio
• Haemophilus influenzae type b (Hib)
• Hepatitis B vaccine
• Varicella vaccine

Decisions regarding administration of other vaccines, such as yellow fever, typhoid, and hepatitis A, which are typically given to travelers before visiting areas of potential outbreak, should be made in consultation with a physician knowledgeable about children’s travel medicine and will likely depend on the degree of infection in the area and the age of the child.

As appropriate for age, the CDC also recommends that international travelers receive:

• Immune Globulin (for resistance to hepatitis A; the standard adult vaccine is not licensed for administration to children under 2 years old)
• Typhoid vaccine (particularly for those visiting developing countries, unless the child is still breastfeeding)
• Malaria medication and prevention (especially for pregnant women and infants)

Malaria, which is a preventable infection that can be deadly if left untreated and is especially dangerous for pregnant women and young children, is endemic in over 100 countries around the world. Parents and children visiting these mostly tropical areas are encouraged to maintain strict vigilance against mosquito bites by wearing long sleeves and pants in the evening, sleeping under bug nets, and keeping to the strict schedule of anti-malaria medication.

Children under 6 months of age who are still breastfeeding have a distinct travel advantage because breast milk contains maternally derived antibodies that protect infants against things like measles (usually treated with MMR vaccine) and typhoid. As a result, vaccination supplements beyond what the mother has been given are generally not needed by breastfed infants, and experts recommend that mobile mothers breastfeed as long as possible.

Of course, many of the diseases confronted by a globe-trotting family are likely to be spread through food and waterborne microbes. The unpleasant but mostly benign “traveler’s diarrhea,” and the more dangerous life threatening infections like E. Coli, salmonella, and hepatitis are all spread through contaminated food and water. Therefore, healthy explorers the world over should heed the traveler’s motto: “Boil it, cook it, peel it, or forget it.”

Dr. Chapnick suggests that “children and nursing or pregnant mothers should pay meticulous attention to their food and beverage choices. Drink only bottled water or carbonated drinks, avoid food from vendor stalls, and wash your hands often.”

Families planning to tour beyond the borders of North America should also check to ensure that their health insurance policy will protect them while in other countries. It’s also a good idea to obtain the phone numbers for English speaking medical experts before you depart.

To view an extensive listing of the recommended, and often required, vaccinations for travel to around the world visit the CDC’s Web site.

Families can also check for pertinent information and guidelines on the CDC’s toll-free hotlines:

• National Immunization Hotline (English) 1-800-232-2522
• National Immunization Hotline (Spanish) 1-800-232-0233
• Traveler’s Health 1-877-394-8747

“We have spent a lot of time researching the issue and discussing it with our pediatrician,” says Rachelle. “It’s really important that we are in control of making an informed decision about where and when to vaccinate. We want to make sure Amani’s journey around the world is as safe and enjoyable for her as it is for us.”

• Schedule of Childhood Immunizations
• Child/Infant Immunization Schedule
• Childhood Immunizations Quiz
• Vaccinations and Your Preschooler