Safety and immunogenicity of the live-attenuated varicella vaccine in pediatric solid organ transplant recipients: A systematic review and meta-analysis.

This study aimed to synthesize the available evidence on the immunogenicity, safety, and effectiveness of live-attenuated varicella vaccine in solid organ transplant recipients. Medline and EMBASE were searched using predefined search terms to identify relevant studies. The included articles reported varicella vaccine administration in the posttransplant period in children and adults. A pooled proportion of transplant recipients who seroconverted and who developed vaccine-strain varicella and varicella disease was generated. Eighteen articles (14 observational studies and 4 case reports) were included, reporting on 711 transplant recipients who received the varicella vaccine. The pooled proportion was 88.2% (95% confidence interval 78.0%-96.0%, 13 studies) for vaccinees who seroconverted, 0% (0%-1.2%, 13 studies) for vaccine-strain varicella, and 0.8% (0%-4.9%, 9 studies) for varicella disease. Most studies followed clinical guidelines for administering live-attenuated vaccines, with criteria that could include being at least 1 year posttransplant, 2 months postrejection episode, and on low-dose immunosuppressive medications. Varicella vaccination in transplant recipients was overall safe in the included studies, with few cases of vaccine-strain-induced varicella or vaccine failure, and although it was immunogenic, the proportion of recipients who seroconverted was lower than that seen in the general population. Our data support varicella vaccination in select pediatric solid organ transplant recipients.
Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: This study was supported by funding from The Hospital for Sick Children Transplant and Regenerative Medicine Centre (TRMC). PPPR has been co-investigator on an investigator-led project funded by Pfizer that is unrelated to this study. JU reports being a past investigator for Sanofi/Regeneron, fees from Pfizer and AstraZeneca, all unrelated to vaccines. SKM has received honoraria for lectures from GlaxoSmithKline, was a member of ad hoc advisory boards for Pfizer, Sanofi Pasteur, and Merck and is a co-investigator on an investigator-led grant from Pfizer, all unrelated to this study. All authors have no conflict of interest relevant to this publication to declare. The authors of this manuscript have no conflicts of interest to disclose as described by the American Journal of Transplantation.
(Copyright © 2023 American Society of Transplantation & American Society of Transplant Surgeons. Published by Elsevier Inc. All rights reserved.)