Drug Interactions between allogeneic processed thymus tissue and measles virus vaccine

GENERALLY AVOID: The administration of live, attenuated viral or bacterial vaccines or live, attenuated virus or bacteria as oncolytic immunotherapy to patients with congenital athymia who have received an allogenic thymocyte-depleted thymus tissue implant but have not yet developed sufficient immune function may be associated with a risk of disseminated infection due to enhanced replication of vaccine virus or bacteria in the presence of inadequate immune competence. Immunizations in patients with congenital athymia have not been shown to be effective prior to the development of immune function post-implant. In addition, immunizations may trigger cytopenias prior to and in the first year after implantation. A review of culture thymus tissue implant program conducted in children with complete DiGeorge anomaly (a condition where children have congenital athymia) in the United States stated that live vaccines were only administered once patients had ceased immunosuppressive therapy(ies) and demonstrated the capacity to mount an immune response to inactivated, killed, or otherwise noninfectious vaccines. The time to development of sufficient immune function is generally 6 to 12 months after treatment with the allogenic thymocyte-depleted thymus tissue implant but may take up to 2 years in some patients.

MANAGEMENT: The administration of live attenuated vaccines or live, attenuated virus or bacteria (as oncolytic immunotherapy) to patients who have received allogenic thymocyte-depleted thymus tissue implant is not recommended. Specifically, the manufacturer recommends that live attenuated vaccines should be avoided until specific immune function criteria are met, including that they have met the criteria for inactivated vaccines and received vaccinations with inactivated agents: that the total CD4+ T cell count is greater than 200 cells/mm3, that there are more CD4+ T cells than CD8+ T cells, as well as the discontinuation of immunosuppressive therapy(ies) and immunoglobulin (IgG) replacement therapy. In addition, the manufacturer advises that no other vaccine (live or inactivated), apart from the inactivated influenza vaccine should be administered within 6 months after administration of a measles-containing vaccine, or within a 2-month period after administration of a varicella-containing vaccine. Verification of immune response is also advised, particularly with respect to varicella- and measles-containing vaccines. The product labeling should be consulted for further recommendations.