Updated: December 30, 2008
About one million children living in the United States are adopted. There are 127,000 new adoptions every year and it is estimated that between 2% and 4% of US families have adopted a child. About 40% of these children are adopted by a family member.
However, increasing numbers of children are adopted from foster care (40%) or from other countries (15%).1 The majority of these children are adopted as infants or toddlers. Internationally adopted children often have resided in orphanages and are from resource-poor countries where many infectious diseases are prevalent.2 In addition, many adopted children have one or more “special needs.”
In contrast to refugee children who have usually undergone medical screening before arrival in the US, internationally adopted children have frequently not had thorough screening for their general health, immunizations, other infectious diseases, anemia, vision, hearing, or development. For these reasons, immigrant children should be evaluated by a health professional shortly after arrival, even if the child appears healthy.
Vaccine providers should only accept written, dated records of prior vaccinations.3 However, even when the medical records and immunization records are available, for internationally adopted it may be difficult to assess how well a child is protected against the different vaccine-preventable diseases or whether the child may be at increased risk for other infections.
More information about vaccines and screening adoptees for infectious diseases can be found in the references provided at the end of this essay. Additional information about the recommended immunization and catch-up schedules is available at www.cdc.gov/vaccines. Families who travel internationally should consider the specific travel recommendations for both vaccines and other diseases prevention for themselves; those recommendations are available for individual countries and regions of countries at www.cdc.gov/travel.
When in doubt, repeating vaccinations is an acceptable and safe option. In many circumstances, immunity could be measured for some of the vaccines when adopted children need other blood tests. Whether immunizations are repeated, blood testing is done, or a combination of these strategies is used, it is important to assure that the child is protected against the vaccine-preventable diseases.
Because vaccine-preventable diseases have occurred among newly arrived international adoptees, the immunization status of internationally adopted children should be assessed soon after their arrival in the US and all needed vaccines administered.
For children more than 5 months of age, there are blood tests available to test for immunity to diphtheria, tetanus, polio viruses and hepatitis B virus. For children over 12 months of age, there are also blood tests available for measles, rubella, chickenpox (varicella) and hepatitis A. The specific blood tests that are recommended for assessing immunity are summarized in reference 2.2
Diphtheria, Tetanus, and Pertussis Vaccines. Numerous diphtheria, tetanus and pertussis vaccines are licensed both in the US and in other countries. In general, these vaccines—including the whole cell pertussis-containing vaccines used throughout most of the developing world and many middle income countries—are as effective as the acellular pertussis-containing (DTaP) vaccines used in the US. However, in one studym many children adopted from orphanages in China, Russia and eastern Europe did not have protective immunity when tested, despite documentation of prior immunization with DTP. Because of the importance of these diseases, many health professionals prefer to test for immunity or re-immunize foreign born children from these countries according to the age appropriate schedule used in the US45—unless they are confident of the accuracy of the records and the quality of the vaccines given.
Haemophilus influenzae, type b Conjugate Vaccine (Hib). Hib vaccine should be administered to all young children. The number of doses required decreases as the child gets older. Hib vaccine is not routinely recommended for children over 5 years of age unless the child has a specific risk factor. More detailed information can be found at http://www.cdc.gov/vaccines/recs/default.htm
Hepatitis A Vaccine. Children under 6 years of age usually have no symptoms of hepatitis A virus (HAV) infection but they can shed the virus in their stool for long periods of time. Older children and adults, on the other hand, typically develop symptoms of hepatitis. Transmission of HAV often occurs among households and extended families and can occur within child care centers. In recent years, international travel has become a major source of HAV outbreaks in the US. For these reasons, families should be immunized against hepatitis A four weeks before an internationally adopted child enters the household or before they embark on international travel (see figure here—travelers to Australia, Canada, western Europe, Japan and New Zealand are at no increased risk than persons residing in the US). If there is insufficient time to assure immunity to HAV (at least 4 weeks), prospective parents should discuss with their health professional whether they and other family members should receive immunoglobulin prophylaxis.
Unless known to be immune, all children should be vaccinated with hepatitis A vaccine when they are 12 months of age or older. For children from countries where hepatitis A is common, it may be cost-effective to screen for prior immunity to hepatitis A virus.
Hepatitis B Vaccine. Because chronic hepatitis B virus infection can cause liver disease and liver cancer decades later and there are now safe and effective drugs with which to treat chronic hepatitis B virus infection, it is important to identify children who have been infected by hepatitis B virus. Blood testing on arrival in the US and again after 6 months is particularly important for all foreign born children, especially those who were born in eastern Europe, Asia, Africa, the Middle East, Pacific Islands, and the children of indigenous peoples of northern Canada and Greenland (see table here). US-born children whose birth parents were from these regions should also be tested. Many experts also recommend that adopted US-born infants—whose mother was not documented to have been screened for hepatitis B virus infection—also be tested.
If the tests show that the child had previously been hepatitis B virus infected, the child does not need to be vaccinated.
If the child is found to have hepatitis B virus infection, he or she should be retested to determine whether infection is acute or chronic. Those with chronic hepatitis B infection should be monitored for liver disease and all household members should be vaccinated. If the child is found to be hepatitis B virus susceptible, he or she should be immunized.
Influenza Vaccine. Young children are at high risk of complications from influenza. All children over 6 months of age need annual immunization against influenza. For children under 6 months of age, the best way to protect them is to immunize everyone in their household, ideally before the baby enters the home. Children 6 months to 9 years of age who are being vaccinated for the first time need two doses of vaccine, separated by at least one month.
Measles, Mumps, and Rubella (MMR) Vaccine. All of these viruses are circulating throughout the world, including western Europe. Although most children in the US receive the combined measles, mumps, and rubella vaccine, many countries do not immunize against mumps or rubella. The simplest approach is to immunize children over 12 months of age with 2 doses of MMR vaccine at the recommended ages. In the US, the doses are usually given at 12-15 months of age and again at school entry (4-6 years of age); however, the doses can be given 4 weeks apart if necessary. Serious adverse reactions to MMR vaccine are rare and there is no evidence that giving the vaccine to children who are already immune to any one of these diseases increases the risk for serious adverse events following immunization.
Pneumococcal Conjugate Vaccine (PCV7). PCV7 vaccine is not used in many countries, so PCV7 vaccine should be administered to all children, the number of doses decreasing as the child gets older. Pneumococcal vaccine is not routinely recommended for children over 5 years of age unless the child has a specific risk factor. More detailed information can be found at http://www.cdc.gov/vaccines/recs/default.htm
Polio Vaccine. Adopted children should be fully immunized against polio viruses, if they are not yet fully immunized. Polioviruses continue to circulate throughout the world and polio continues to occur in South Asia (Utter Pradesh and Bihar states in India; Pakistan; and Afghanistan) and Africa (Nigeria has the most of any country, particularly in the northern states). They are only a plane ride away. In the US, children are immunized with the inactivated poliovirus vaccine, which is given by injection. The oral vaccine—which is still used in much of the world—should also be effective.
Varicella Vaccine. Unless the child has had a documented history of having had chickenpox, 2 doses of the varicella vaccine should also be given at the appropriate ages.
In addition to the vaccine-preventable diseases, parents should consider having their adopted children tested for the following infections:
Hepatitis C Virus. Children who are infected with hepatitis C virus may develop chronic liver disease and liver cancer as adults. There is no vaccine against hepatitis C but children with persistent hepatitis C infection need to be identified so that they can be monitored for the development of liver disease for which there is treatment. Many experts recommend screening foreign born children for hepatitis C initially and again in 6-12 months if the child was born in China, Russia, eastern Europe or Southeast Asia. All children should be screened if the child may have received blood products or if there was a history of maternal drug use.56
Human Immunodeficiency Virus (HIV). There is no vaccine against HIV but there are drug treatments that are more effective the earlier they are begun, including for infants born to HIV infected mothers. Because screening for HIV is inconsistent in many countries, international adoptees should be tested for infection by HIV1 and 2. In the US, mothers are usually screened for HIV infection in order that the child may be treated. Most authorities believe that US-born children should also be screened for HIV 1 and 2 infections if documentation of the mother’s test is not available.
Parasites. Many international adoptee children have intestinal parasites. The types vary according to the birth country. Because children with intestinal parasites may experience growth delay and anemia, these children also need to be screened for intestinal parasites on arrival by comprehensive microscopic examination of multiple stool samples.256
Syphilis. There is no vaccine against syphilis but it remains susceptible to penicillin. Many countries screen and treat appropriately for congenital syphilis. However, sometimes foreign born children have undiagnosed and untreated syphilis, so children need to be screened on arrival. Children with treated congenital syphilis need to have clinical evaluations repetitively until they are 12 months old.
Tuberculosis. Children under 5 years of age are more susceptible to tuberculosis than older individuals and they are more susceptible to invasive, fatal forms of tuberculosis. Foreign-born children from many countries—especially those born in Asia, the Middle East, Africa, Latin America, and the countries of the former Soviet Union—are at increased risk for tuberculosis. Many foreign born children will have received the bacilli Calmette-Guérin (BCG) tuberculosis vaccine, which is not commonly used in the US.
Many authorities recommend that a chest x-ray be obtained on children who have a history of tuberculosis in a family member or who have been adopted from a country where the prevalence of tuberculosis is very high—in order to detect early evidence of tuberculosis infection.
All internationally adopted children should be screened for tuberculosis by a PPD skin test. If the skin test is negative, it should be repeated after 8-10 weeks. If the test is positive the child will need additional testing. Distinguishing skin test reactions due to tuberculosis infection from those due to immunization with BCG can be difficult; some consider the QuantiFERON®-TB Gold test useful in this setting, although experience in interpreting this test in young children, is limited. US-born children—and those born in Canada, Australia, New Zealand or Western Europe—should also be screened for tuberculosis if the child has risk factors such as parental incarceration or HIV infection, or if the maternal history is unknown.7