Factors associated with protective antibody levels to vaccine preventable diseases in internationally adopted children

Abstract

To determine which factors are predictive of protective antibody against vaccine-preventable diseases in internationally adopted children, we evaluated 562 children with serologic testing for at least one vaccine antigen before receiving a US vaccination. Vaccination status was defined as the number-of-doses recorded and as the presence of an up-to-date and valid record according to the American Academy of Pediatrics and the Advisory Committee on Immunization Practices guidelines. The number-of-doses recorded was the best predictor of protective antibody. These findings suggest that other options for immunization verification guidelines for internationally adopted children should be considered by policy makers.

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

“…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.…”

“…[2,16,29,30] Each country has a different geographic profile of IAC, thus medical problems in these children could vary according to their origin. 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.…”

Systematic review shows that immunising internationally adopted children is a major challenge for primary health care

“…The primary search identified 749 records. The titles and abstracts were screened, 41 full-text papers were assessed for eligibility, and 19 studies fulfilled our inclusion criteria (Table 1) (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). These studies were conducted between 1988 and 2016 and covered 7663 children aged between 1.1 and 5.7 years, who were adopted from Asia, Eastern Europe, Africa and South and Central America.…”

“…Tetanus protective antibody levels were observed in 35–95% of adopted children, and similar data were reported for diphtheria . A higher percentage of adoptees had protective antibody levels for polio and measles, varying from 57 to 90% and 36 to 90%, respectively . Data from a study conducted by Sollai et al., published in 2017, showed that 15.7% of internationally adopted children did not have protective antibody titres against tetanus, 26.4% did not have them against diphtheria, and the figure for Hepatitis B was 35.1%.…”

Seroprevalence of antibodies against vaccine preventable diseases in internationally adopted children

“…The immunization status of internationally-adopted children at their arrival in the host country should be carefully checked, in order to provide them with the best available vaccination opportunities and for proper placement within the community [2,3]. A serologic evaluation is usually required, because of the frequent lack of complete and reliable vaccination records in adoptees' countries of origin [4,5]. Emilia-Romagna, the northern Italy region where this study was performed, approved in 2007 an official procedure, which includes the serologic assessment of adopted children concerning transmissible and vaccine-pre-ventable diseases [6].…”