Vaccine-Mediated Immunity in Survivors of Childhood Cancer: A Scoping Review

Advances in childhood cancer treatment have dramatically improved survivorship such that ∼1 in 500 Americans is a survivor of childhood cancer. Although short-term treatment effects are well documented, late effects on humoral immunity remain underexplored. Declining general vaccination rates, combined with under-protection among survivors, heightens the risk for vaccine-preventable diseases (VPDs) in this population. A scoping review was conducted on three research databases (PubMed, Embase, and Web of Science) following the Joanna Briggs Institute systematic methodology and Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews guidelines. Eligible studies included survivors aged 0-21 at diagnosis treated with non-transplant cancer therapies that reported humoral immune outcomes (titers, CD4, and IgG recovery). Twenty-three studies were included. All studies reported loss of immunity to at least one VPD following cancer treatment. Inactivated vaccines showed low posttreatment protection (≤50%) but strong recovery following revaccination (≥90%). Live attenuated vaccines demonstrated inconsistent baseline protection (9%-75%), with postvaccination immunity averaging ∼72%. Younger age at diagnosis was most consistently associated with reduced immunity, whereas disease type and treatment intensity were less reliably linked. Pediatric cancer survivors frequently lack protective immunity to VPDs following treatment. Revaccination with inactivated vaccines appears effective, but responses to live attenuated vaccines remain suboptimal.