IAC Study Finds Immunization of Most Internationally Adopted Children Can Be Verified
By Indi Trehan, MD, MPH, and Mary Allen Staat, MD, MPH
There has been much debate over whether the immunization records of internationally adopted children could be trusted and even further controversy over how to manage immunizations in international adoptees without an immunization record. Results from a small pilot study from the International Adoption Center (IAC) at Cincinnati Children's Hospital Medical Center three years ago impacted national guidelines for both the Centers for Disease Control (CDC) and the American Academy of Pediatrics (AAP) such that two approaches were recommended:
- either reimmunize internationally adopted children
or - Do antibody testing to verify whether the child is adequately protected from vaccine preventable diseases
Over the past six years, it has been the practice of the IAC to verify the immunization status of children seen in the IAC. Using the data from the children seen in our center we sought to determine whether internationally adopted children have serological evidence (antibodies) of immunity to vaccine-preventable diseases regardless of whether there is any documentation of immunization from the child's birth country. This study was approved by the Institutional Review Board utilizing a limited data set agreement.
Over the nearly five years of study, 740 children, who were five months or older and had not received any immunizations in the US were included in the study. Most (83%) had some documentation of receiving some immunizations from their birth country regardless of their country of origin. Our results found children with documentation of immunizations from their birth country had the highest levels of protection with more than 85% protected for diphtheria, tetanus, polio, measles and rubella. Even in those children without documentation of immunizations from their birth country, many children had evidence of protection to many vaccine-preventable diseases and thus could receive fewer immunizations than if they had just repeated all immunizations in the US.
Another important finding of our study is that there were not major differences in evidence of protection by birth country. Many adoption professionals have stated that records could be "trusted" from Guatemala and Korea but not from other countries. We did not find that one country was more reliable than another. In other words, even Guatemalan and Korean adoptees with documentation of immunizations from their birth country, were not always found to have protective levels of antibody and thus their records could not always be verified. In general, the proportion of children with protection was comparable regardless of the child's birth country with the exception that children from China had slightly lower levels of protection than children from other countries.
Another finding was that the majority of children (93%) older than two years of age with or without a history of measles vaccine had evidence of protection against measles. Thus, most older adoptees have either been immunized for measles or have had measles and are protected. We also found that if children had a history of chicken pox (varicella) in their birth country, 83% were found to have antibodies to varicella (thus verifying that history).
Our findings are important in that we now have country-specific data for a large number of international adoptees that strongly demonstrates that regardless of the child's birth country the vast majority of internationally adopted children are being vaccinated and that these vaccines provide good protection. In light of these findings, it is our hope that the AAP and CDC recommendations for immunization of internationally adopted children be revisited so that internationally adopted children do not get re-immunized unnecessarily.
This work was done with the help of so many people. Indi Trehan, MD, MPH, conducted the analyses and presented the results at the annual Pediatric Academic Societies' Meeting in Washington DC in May, 2005. Not only was this study presented as a poster symposium at the meeting, Dr. Trehan also received the Regional Ambulatory Pediatric Society's Resident Award for this work on this project. In addition, each summer, students from the High School Summer Intern Program abstract data on the children seen in the IAC. Without this effort, this study could not have been done. We would also like to thank all the wonderful families and their children who contributed the data for the study. It is our hope that through the work done we will be able to provide data that will allow improvements of the care of internationally adopted children not only in Cincinnati but around the world.
