Immunization status of internationally adopted children in Italy

Infectious diseases prevalence, vaccination coverage, and diagnostic challenges in a population of internationally adopted children referred to a Tertiary Care Children's Hospital from 2009 to 2015

“…These data are similar to those recently published, [13,15,17,19] confirming that IAC should be tested rapidly for their immunization status on arrival in the adopting country, because they are not protected in a sufficient way against vaccine-preventable diseases. Moreover, preadoptive immunization records are often lacking and scarcely reliable [13,15,17,19] : indeed, in our population vaccine documentation was available in only 38.9% to 46.1% of the cases (mostly in European children), with a variable discrepancy between available documentation and test results (ranging from 9% for tetanus and 24.1% for HBV).…”

“…Moreover, preadoptive immunization records are often lacking and scarcely reliable [13,15,17,19] : indeed, in our population vaccine documentation was available in only 38.9% to 46.1% of the cases (mostly in European children), with a variable discrepancy between available documentation and test results (ranging from 9% for tetanus and 24.1% for HBV). Some authors reported that in a population of 562 IAC the number of doses recorded was the best predictor of protective antibody titer, [71] but in our study, 52/616 (8.4%) children with ≥3 doses of tetanus vaccine had a nonprotective antibody titer.…”

“…Most of the literature data come from United States studies, [3–5,9,14,20–22,24,26,28] and only few reports have investigated the health status of IAC in Europe. [2,10,13,15–19,29,31–36] Prevalence of medical problems was described in more than 40% of the cases by van Schaik and colleagues in The Netherlands. [13] Other authors found a substantially higher risk of hospitalization or the need for a specialistic consultation in IAC with respect to not-adopted children.…”

Serologic testing to verify the immune status of internationally adopted children against vaccine preventable diseases

“…We found high levels of the proportion protected overall (90%) and by each serotype (93–95%) using a definition of protection of ≥1:8. The overall proportion protected ranged from 50% to 86% in other studies [6,7,9–13]. When we analyzed our data using a titer of ≥1:32 to compare to the Verla-Tebit study [12] which used ≥1:40, we still had higher levels of overall protection (84%) and to serotypes 1–3 (87%, 93%, and 90%, respectively) compared to their study which had 58%, 82% and 52% with protective antibody for serotypes 1–3, respectively.…”

“…The countries evaluated, ages of children studied and laboratory methods used may account for some of the differences seen between studies. Some studies presented data for children with ≥3 doses, without indicating how many additional doses were given [5–7,9,11,12]. In order to make direct comparisons with the existing literature, we have presented our data by the specific number of doses as well as by ≥3 doses of vaccine for diphtheria, tetanus, polio, and HBV and ≥1 dose for measles, mumps, rubella, and varicella.…”