Effective and safe immunizations with live-attenuated vaccines for children after living donor liver transplantation

Area of Science:

• Pediatric Gastroenterology and Hepatology
• Immunology
• Transplant Medicine

Background:

• Live-attenuated vaccines are generally contraindicated in pediatric liver transplant (LT) recipients due to theoretical risks.
• Post-LT children face exposure to vaccine-preventable viral diseases in community settings.
• Assessing the safety and efficacy of live-attenuated vaccines is crucial for this vulnerable population.

Purpose of the Study:

• To evaluate the safety and immunogenicity of live-attenuated vaccines in pediatric living donor liver transplant (LDLT) recipients.
• To determine seroconversion rates and assess adverse events following vaccination.
• To investigate the durability of immune response after vaccination.

Main Methods:

• Seventy immunizations with four live-attenuated vaccines (measles, rubella, varicella, mumps) were administered to 18 pediatric LDLT recipients meeting specific immunity criteria.
• Seroconversion rates were assessed after the first vaccine dose.
• Patients were monitored for clinical diseases and serious adverse effects for up to 5 years and 11 months.

Main Results:

• High seroconversion rates were observed: 100% for measles and rubella, and 82% for varicella and mumps.
• Waning immunity was noted in some cases, except after rubella immunization.
• No clinical diseases or serious adverse effects related to the immunizations were reported.

Conclusions:

• Selected live-attenuated vaccines are safe and effective in pediatric LDLT recipients with adequate humoral and cell-mediated immunity.
• Vaccination strategies should be considered for post-LT children to prevent vaccine-preventable diseases.
• Careful patient selection and monitoring are essential for successful live-attenuated vaccine administration in this cohort.