Successful serology-based intervention to increase protection against vaccine- preventable diseases in liver-transplanted children: A 19-yr review of the Swiss national reference center Infectious diseases represent a significant threat for patients before and especially after SOT (1, 2). Children undergoing SOT are at higher risk of vaccine-preventable illnesses, not only because of immunosuppression after transplantation, but also because of their immunological naivete´ . Recommendations for immunizing SOT patients are well established for most vaccines (3–5). In Europe, they include all usual vaccines proposed to healthy children: D, T, aP, Hib, HBV and, before transplantation only because this vaccine is a live attenuated vaccine, MMR. Recommen- dations may also include additional vaccines, such as VZV, SPn and HAV (6–8). Despite these recommendations, a review of vaccine strategies offered to all children with OLT in Switzerland between 1990 and 2002 showed that they were not fully followed (9). Consequently, the authors established new recommendations for our national reference center. These included LÕHuillier AG, Wildhaber BE, Belli DC, Diana A, Rodriguez M, Siegrist CA, Posfay-Barbe KM. Successful serology-based intervention to increase protection against vaccine-preventable diseases in liver- transplanted children: A 19-yr review of the Swiss national reference center. Pediatr Transplantation 2012: 16: 50–57. Ó 2011 John Wiley & Sons A/S. Abstract: As children referred for OLT in Switzerland were not vacci- nated optimally, new guidelines were developed and recommended to base catch-up immunization on serum antibody titers against vaccine- preventable diseases, before and after OLT. We measure the results of this serology-based intervention by comparing vaccine coverage and antibody titers in the pre- (1990–2002, P1) and post-intervention (2003– 2008, P2) cohorts in a quality control project. Forty-four P1 and 30 P2 children were evaluated. At pre-OLT visit, D, T, SPn, and MMR se- rologies were checked more frequently in P2 than P1 (p < 0.05). More P2 children were up-to-date for DTaP and MMR (p < 0.05) or had received ‡1 dose of HBV, HAV, SPn, and VZV vaccines (p < 0.05). One yr post-OLT, DT, SPn, MMR, and VZV serologies were more frequently checked (p < 0.05), and antibody titers were higher for DT and HAV (p < 0.05) in P2. Gender, age, or diagnosis did not explain these differences. Among P2 patients, pre- and post-OLT titers for D, T, Hib, HBV, SPn14, and SPn19 were correlated (p < 0.05 for all). Pro- tection against vaccine-preventable diseases of high-risk children like OLT patients can be significantly improved by serology-based inter- vention for vaccine-preventable diseases. A. G. LÕHuillier 1 , B. E. Wildhaber 2 , D. C. Belli 1 , A. Diana 1 , M. Rodriguez 1 , C. A. Siegrist 1,3 and K. M. Posfay- Barbe 1,3 1 Department of Pediatrics, University Hospitals of Geneva, 2 Department of Pediatrics and Pediatric Surgery, University of Geneva, 3 Geneva Medical School, University of Geneva, Geneva, Switzerland Key words: liver transplantation – children – immunization – vaccines – antibodies – serology Klara Posfay-Barbe, MD, MS, ChildrenÕs Hospital of Geneva, 6, rue Willy-DonzØ, 1211 Geneva 14, Switzerland Tel.: +41 22 382 5462 Fax: +41 22 382 5490 E-mail: klara.posfaybarbe@hcuge.ch Accepted for publication 1 September 2011 Abbreviations: aP, acellular pertussis; D, diphtheria; DT, diphtheria-tetanus; DTaP, diphtheria–tetanus–pertussis; HAV, hepatitis A virus; HBV, hepatitis B virus; Hib, Hae- mophilus influenzae type b; IQR, interquartile range; MMR, measles–mumps–rubella; OLT, orthotopic liver transplan- tation; SOT, solid organ transplantation; SPn, Streptococ- cus pneumoniae; T, tetanus; VZV, varicella-zoster virus. Pediatr Transplantation 2012: 16: 50–57 Ó 2011 John Wiley & Sons A/S. Pediatric Transplantation DOI: 10.1111/j.1399-3046.2011.01600.x 50