Common Live Vaccines May Be Safe for Specific Pediatric Patients Who Are Recipients of Solid Organ Transplant

Live vaccines could be safe and immunogenic for pediatric patients who have received a solid organ transplant (SOT), according to findings from a recent study published in JAMA Network Open. Investigators evaluated live vaccination against measles-mumps-rubella (MMR) and varicella-zoster virus (VZV) for pediatric SOT recipients taking low-level monotherapy immunosuppression, discovering that most children had a durable immune response.

Image credit: weyo | stock.adobe.com

“The majority of children developed protective antibodies after receiving between 1 and 3 doses of MMR, VZV, or both vaccines [and] at 1 year post vaccination, the majority of children who initially mounted protective antibodies maintained protection,” the study authors wrote in the article.

Children with SOT are often considered to be immunocompromised, so live vaccination was not traditionally recommended for fear of vaccine strain infection) However, in 2019, the American Society of Transplantation and the International Pediatric Transplant Association began recommending live MMR and VZV vaccines to select nonimmune SOT recipients who were receiving low-level immunosuppression at more than 1-year post-transplant.

A recent cohort study evaluated the safety and immunogenicity of live vaccines for circulating measles, mumps, and varicella in pediatric patients who received a SOT (liver or kidney). To understand immunogenicity, investigators evaluated antibody levels at 0 to 3 months and 1-year post-vaccination.

In the 1 to 3 months following vaccination, approximately 72% of children vaccinated against varicella had antibodies. Antibodies were present in 86% of children vaccinated against measles, 83% vaccinated against mumps, and 99% vaccinated against rubella.

After 1 year, most of the children maintained a level of protection against these viruses: 77% presented antibodies for varicella, 92% for measles, 83% for mumps, and 94% for rubella. The safety data were also positive, as no children experienced severe adverse events, such as graft injury or death.

The current study evaluated 281 pediatric liver and kidney transplant recipients (270 [96%] liver, 9 [3%] kidney, and 2 [1%] liver and kidney recipients) who originally participated in the LIVE VAC study, which was conducted to administer live vaccines to nonimmune patients with SOT who had not received a primary series of live MMR or VZV vaccines.

Patients came from 18 pediatric SOT centers and met eligibility criteria designated by American Society of Transplantation: low level immunosuppression, were more than 1 year past transplant, more than 2 months post-rejection, and had age-appropriate absolute lymphocyte count.

Limitations of the study include its observational design; variable criteria for vaccine eligibility; incomplete data on vaccine history and antibody levels prior to SOT; a small number of patients who received a kidney transplant; and not all participants had antibodies tested at 1-year post-transplant.

“Dissemination of safety and immunogenicity data and sharing of effective implementation strategies and outcomes could be important to accelerate adoption of these novel recommendations across SOT centers,” the study authors concluded. “Further research is needed to understand long-term maintenance of immunity after live post-SOT vaccination in pediatric recipients, as well as factors associated with immune response and clinical protection.”

Reference

Feldman A, Beaty B, Ferrolino J, et al. Safety and Immunogenicity of Live Viral Vaccines in a Multicenter Cohort of Pediatric Transplant Recipients. JAMA Netw Open. 2023;6(10):e2337602. DOI:10.1001/jamanetworkopen.2023.37602