Vaccinations in children with hematologic malignancies and those receiving hematopoietic stem cell transplants or cellular therapies

Abstract

AbstractChildren who are immune compromised are uniquely threatened by a higher risk of infections, including vaccine‐preventable diseases (VPDs). Children who undergo chemotherapy or cellular therapies may not have preexisting immunity to VPDs at the time of their treatment including not yet receiving their primary vaccine series, and additionally they have higher risk of exposures (e.g., due to family structures, daycare and school setting) with decreased capacity to protect themselves using nonpharmaceutic measures (e.g., masking). In the past, efforts to revaccinate these children have often been delayed or incomplete. Treatment with chemotherapy, stem cell transplants, and/or cellular therapies impair the ability of the immune system to mount a robust vaccine response. Ideally, protection would be provided as soon as both safe and effective, which will vary by vaccine type (e.g., replicating versus nonreplicating; conjugated versus polysaccharide). While a single approach revaccination schedule following these therapies would be convenient for providers, it would not account for patient specific factors that influence the timing of immune reconstitution (IR). Evidence suggests that many of these children would mount a meaningful vaccine response as early as 3 months following completion of treatment. Here within, we provide updated guidance on how to approach vaccination both during and following completion of these therapies.